Automotive speed control system

ABSTRACT

An important disclosure herein comprises an automatic speed control system for an automotive vehicle including mechanism providing a selective mode of operation which enables the driver when he chooses to resume a previously set regulated speed subsequent to slowing or stopping the vehicle. This selective control mechanism enables &#39;&#39;&#39;&#39;automatic&#39;&#39;&#39;&#39; reactivation of the speed control device in response to a change in accelerator movement and is accomplished by selective advancement of the accelerator slightly beyond its normal driving position to initiate automatic acceleration to the regulated speed. Several forms of restraining means are provided to make this mode of operation completely safe by automatically rendering the device inoperative, for example when the driver opens a vehicle-door. In another form of restraining means, the device is rendered completely inoperative whenever the vehicle speed falls below a set value, such as 20 mph for example. Also, specific forms of curve-compensation may be added to this or any speed control system to provide additional safety, in which the regulated vehicle speed is automatically caused to reduce temporarily on road curves, and to return to the regulated speed when the road is again straight.

United States Patent [1 1 Thorner 11] 3,777,841 Dec. 11, 1973 1AUTOMOTIVE SPEED CONTROL SYSTEM [76] Inventor: Robert 11. Thorner,8750-F W.

Chicago Blvd., Detroit, Mich. 48204 [22] Filed: June 3, 1970 [21] Appl.No.: 43,122

Related US. Application Data [52] US. Cl. 180/108, 123/103 R [51] B60k31/00 [58] Field of Search 180/105, 106, 107,

[56] References Cited UNlTED STATES PATENTS 2,432,166 12/1947 Mallory180/77 R 3,092,090 6/1963 Berninger... 180/108 X 3,245,494 4/1966 Baxter180/108 2,016,864 10/1935 Lange 192/.058 2,359,231 9/1944 Mallory....123/103 2,302,322 11/1942 Howard 180/105 2,740,947 4/1956 Davies 180/105X 2,990,825 7/1961 Fuller et a1. 180/106 X 3,023,828 3/1962 Fuller eta1. 180/109 3,100,021 8/1963 Maurer et a1. 180/109 3,305,042 2/1967Thorner 180/108 X 3,322,227 5/1967 Thorner 180/108 11/1969 Thorner180/108 1/1970 Thorner ..180/108 Primary Examiner-Kenneth H. Betts {57]ABSTRACT An important disclosure herein comprises an automatic speedcontrol system for an automotive vehicle including mechanism providing aselective mode of operation which enables the driver when he chooses toresume a previously set regulated speed subsequent to slowing orstopping the vehicle. This selective control mechanism enablesautomatic" reactivation of the speed control device in response to achange in accelerator movement and is accomplished by selectiveadvancement of the accelerator slightly beyond its normal drivingposition to initiate automatic acceleration to the regulated speed.Several forms of restraining means are provided to make this mode ofoperation completely safe by automatically rendering the deviceinoperative, for example when the driver opens a vehicle-door. Inanother form of restraining means, the device is rendered completelyinoperative whenever the vehicle speed falls below a set value, such as20 mph for example. Also, specific forms of curvecompensation may beadded to this or any speed control system to provide additional safety,in which the regulated vehicle speed is automatically caused to reducetemporarily on road curves, and to return to the regulated speed whenthe road is again straight.

38 Claims, 18 Drawing Figures 1 AUTOMOTIVE SPEED CONTROL SYSTEM Thepresent application is a continuation-in-part of Ser. No. 668,121, filedSept. 15, 1967, entitled, Automotive Speed Control System, now US. Pat.No. 3,528,523, which in turn is a division of Ser. No. 430,910, filedFeb. 8, 1965, entitled Automotive Speed Control System, now US. Pat. No.3,343,423, which contain subject matter relating to the inventionsdisclosed in my following patent applications: Ser. No. 283,272, filedMay27, 1963, entitled Speed Regulating Device97 (now abandoned), whichis a divisional case of Ser. No. 74,315, filed Dec. 7, 1960, entitledVehicle Speed Regulating Device, now U.S. Pat. No. 3,153,325; Ser. No.82,769, filed Jan. 16, 1961, entitled Speed Regulator Device," now US.Pat. No. 3,213,691; Ser. No. 118,411, filedJune 20, 1961, entitledThrottle Control Mechanism, now 13.8. Pat. No. 3,168,933; Ser. No.266,257, filed Mar. 19, 1963, entitled Automotive Speed ControlApparatus, now US. Pat. No. 3,305,042 and Ser. No. 316,987, filed Oct.17, 1963, entitled, Automotive Speed Control Systern, now US. Pat. No.3,222,227.

With the increasing use of non-stop highways, sometimes referred to asturnpikes, thruways, freeways, etc., there is an increasing need for anautomatic throttle for automotive vehicles. When an automobile is drivenfor long distances on these non-stop highways, the operators foot andleg muscles become tired'and strained due to the necessity of holdingthe accelerator in various desired positionsfor long'periods of time. Amain purpose of all Automatic Throttle devices, as disclosed herein, isto enable the vehicle operator to drive without the necessity of holdinghis footon the accelerator. Such devices are now believed to add safetyin operating automotive vehicles because (1) they reduce fatigue,thereby reducing the tendency to fall asleep and making the driver morealert inall emergencies, (2) they maintain a selected speed, whereasinnormal driving it is easy on long trips to exceed the intended speedunknowingly.

At the present state of the art, there is a wide difference of opinionamong people at the automotive firms regarding what is'desired for suchspeed control devices. These devices generally comprise (l) some type ofmeans to regulate vehicle speed, either automatically (with a governormechanism) or manually (handthrottle), and (2) a selective controlsystem to determine when and how the speed-regulating means is operatedand rendered inactive or inoperative, and also to select the operatingspeed, etc.

A large difference in opinion exists particularly in the selectivecontrol system for the governing mechanism. Some of my present beliefsare discussed extensively in said application, Ser. No. 266,257. Some ofthese views, of course, may have to be altered in accordance witheventual public opinion, because of ultimate acceptance or rejection ofthe various systems offered. However, based on public acceptance todate, 1 presently believe that the eventual market will be large enoughto support at least two basic automatic governor-type speed controls inaddition to a good handthrottle (manual speed control). The first typeof device is presently available to the public and comprises a qualityspeed control system. Such devices probably will find its largest saleon medium priced and luxury vehicles, and possibly for luxury models oflower priced vehicles. My said application, Ser. No. 266,257 discloses acontrol system that might fall in this category, as it provides featuresdesired by some people (such as accelerator-resistance) who would pay apremium for such features. My centrifugal-liquid sensing and thegoverning system disclosed in my US. Pat. Nos. 3,068,849 and 3,084,758provide such excellent governing characteristics to qualify as aquality" governing device.

In certain regulator applications, such as for an automotive speedregulator in turnpike driving, reduction ofcost is'highly critical inorder for such devices to gain wide public acceptance. Such desirablereduction of cost can best be achieved by inherent simplification of themechanism, which may be justified even at some compromise in performancefrom that produced by the structures disclosed in my said co-pendingapplications. I believe that the eventual market will support a secondeconomy speed control system in addition to the quality system discussedabove. Such economy" device will include a true closed-loop governingmechanism and a control system therefor, but all with certaincompromises to enable low-cost manufacture. Such a device will desirablysell to the consumer at a price somewhat less than the price of thequality device. v v

A main object of the present invention is to provide a governor-typespeed control system for an automotive vehicle particularly, but notnecessarily, for carbureted internal combustion engines and which isvery simple in construction thereby lending itself to low costmanufacture, and also disposed for simple installation in any kind ofautomotive vehicle.

Automotive speed control devices offered commercially either must bemanually reset after each brake actuation or thevehicle is automaticallyplaced under control of the speed regulator only if and when the presetgoverned speed is attained. With the latter type control system, thevehicle driver, after turning the ignition key to its on position, mustmanually set the regulator control at least once in order to enableautomatic operation; thereafter, the driver must wait until he manuallyaccelerates the vehicle to the actual preset regulated speed before hecan remove his foot from the accelerator. When the brake is depressed,the speed regulator is inactivated, but again the preset speed must beattained before the speed regulator again assumes control of the engine.After braking the vehicle to a stop, the speed regulator is renderedinoperative by restraining means operated upon turning off the ignitionswitch, so that the next driver must manually activate the speed controlonce after turning on the ignition switch.

The present invention relates in part to a novel control system for anautomotive speed regulator mechanism which provides a vastly improvedoperation over the present control systems described above. The mainutility of the control system of the present invention is to enableautomatic activation of the control system only after partial butselective temporary advancement of the accelerator at a low speed, andthen to provide completely automatic acceleration up to the preset speedat any time the driver chooses to employ such automatic activation. Whenthe accelerator is deliberately and selectively advanced partially bythe vehicledriver, wherein the vehicle attains a speed somewhat lessthan the preset speed, the speed regulator device is activated andautomatically accelerates thevehicle moderately to the set speed. Thisautomatic acceleration action, which has been called resume-speed, ismore desirable than the action of present control systems as abovedescribed because (1) the operator does not have to wait until the setspeed is attained each of the many times the device must'be engaged innormal driving, and (2) the vehicle-operator can remove his foot fromthe accelerator and the vehicle will automatically seek out and stopaccelerating at exactly the preselected speed in each of the many timesthe speedgovernor. action must be inactivated and re-activated in normaldriving, and (3) by using the Braille system of speed selection, thevehicle-driver never has to look at the speedometer once he has learnedthe clock" positions of the speed-setting knob, as will be described.

In actual practice I have found that these advantages greatly expand theuse of such speed control apparatus to include city and particularlysuburban driving, (on main fast streets and boulevards) between therushhours of traffic, as well as for highway and turnpike driving, to bediscussed further. This is true because my control system providesautomatic acceleration in addition to automatic engagement. In boulevarddriving in light traffic, it frequently requires about one-half thedistance between stop lights to attain the preset speed; hence, in thisexample, not more than one-half of this distancecan be under automaticcontrol. I have found that in clear or light traffic about 90 percent ofthis travel can be under control of the speed regulator. In general,I'have found that driving an automotive vehicle with the type of controlsystem disclosed herein, increases the utility and driving pleasure to adegree which is very difficult to convey in words.

In order to achieve this highly desirable result, many puzzling problemshad to be solved. It is essential that the system be completely safe andthat no driver is ever surprised or startled suddenly by automaticacceleration when unexpected. For this reason, the ignition switch (orany other factor of engine operation) by itself is not acceptable as ameans for operating the restraining means to render the speed controldevice inoperative because it would not detect a change in drivers atall times. This is true because the driver frequently leaves the vehiclewhile the engine is idling, and the next driver might be dangerouslysurprised when he advances the accelerator entirely unaware that thevehicle can be automatically engaged and accelerated.

My hand-throttle devices (such as Ser. No. 118,411 filed June 20, 1961,now U.S. Pat. No. 3,168,933) inherently produce a slow accelerationafter automatic engagement. But governor or similar closed loop speedcontrol devices tend to accelerate the vehicle rather rapidly, and undersome circumstance can produce a dangerous roar of the engine that canstartle the operator. Accordingly, a second problem is to provide thatthe rate of automatic acceleration is moderate.

Another puzzling problem in providing safe automatic acceleration(resume-speed) is that the automatic activation or engagement cannot bespeedresponsive as provided in present speed regulator dematically tothe preset speed each and every time this lower speed is attained. Thistype ,of automatic engagevices. For example, assume that the regulatedspeed is set for 60 mph and the automatic engagement always occurs at 30mph; and the vehicle is accelerated automent and acceleration wouldoccur at all times, even if the driver does not want or expect it;furthermore, the automatic engagement would occur at the same speedevery time. The control system of the present invention is madeselective since the automatic engagement occurs as a function ofadvancement of the throttle at the discretion of the driver completelyindependent of vehicle speed. I have found this method to be trulyselective since the activation or engagement can be made to occur at anydesired speed below (or even above) the preset speed.

Thus, in order to make this desirable control mode of operationavailable to the public, it is necessary to provide ample safety meansto preclude any possibility of a surprise factor in any drivingsituation. Ample safety means are disclosed herein as will be described.

A very important object of the present invention is to provide a controlsystem for an automatic throttle governor or speed regulator mechanismin an automotive vehicle, as recited in the preceding object, whichrequires the operator to partially and temporarily advance the controlmeans deliberately in order to effect an automatic engagement oractivation of the speed governor mechanism; and wherein such engagementis indicated to the operator by signal means dependent on the senses ofsound and/or touch, and he then can remove his foot from the acceleratorsubstantially before the set speed is attained; and thereafter the speedcontrol apparatus effects automatic acceleration of the vehicle up tothe preset speed, and such speed is automatically maintained thereafterin all vehicle attitudes.

In the automatic acceleration feature of the present invention as statedabove, when an automatic speed governor mechanism is included, a highrate of acceleration is sometimes produced which is hazardous. In myhand throttles, such as disclosed in said application Ser. No. 118,411,the rate of automatic acceleration is inherently slow and hence I havefound such devices to be completely safe for automatic acceleration. Mysaid applications, Ser. Nos. 74,315 and 82,769, disclose automaticacceleration which is effected after partial advancement of the controlmeans. Means are disclosed in my said application, Ser. No. 266,257, toretard the rate of automatic acceleration comparable to the inherentrate of acceleration with my hand throttle devices or to theacceleration with normal safe driving of any automotive vehicle.

Another object of the present invention is to provide an automotivespeed control apparatus including a control system, as above recited,and also an automatic speed regulating mechanism, in which novel meansare provided utilizing an inherent characteristic of manifold vacuum (ofa carburetted internal combustion engine) without added mechanism toeffect a retarded or safe rate of automatic acceleration.

Another important object of the present invention is to provide anautomotive speed control apparatus including a control system, asrecited in the second preceding paragraph, and also a speed regulatingmechanism in which novel mechanism is provided to retard the rateof'automatic acceleration upon engagement or activation ofthespeedregulating mechanism and become ineffective upon attaining thepreselected speed after said automatic acceleration.

An additional object of the present invention is to provide anautomotive speed-control system by itself or as described in any of thepreceding objects, including a simple speed governor or regulatormechanism which includes novel means to enable automatic operationthereof only after the vehicle is manually accelerated to a speedslightly above the idle speed but below the lowest governed speed,wherein the regulator mechanism cannot be operated when the vehicle isat rest.

Another object of the present invention is to provide an automotivespeed control apparatus including a control system, and an automaticspeed regulating mechanism in which restraining means are providedoperable, in-one form, upon opening the vehicle door to render theautomatic speed regulating mechanism inoperative until deliberatelyactivated by the vehicle operator after entering the vehicle and closingthe door; and in other forms such restraining means may be operated bythe transmission manual control lever, or by the vehicle seat, or anyother such vehicle element normally operated manually and selectively bythe vehicle operator incident to his leaving (or entering) the vehicle;and in still another form, such restraining means may be operated by thespeed-sensing forces to automatically render the device completelyinoperative when the vehicle speed falls below a predetermined value.

Another object of the present invention is to provide an automotivespeed-control system of the type described in the preceding paragraphsand having a carbureted internal combustion engine, in which enginevacuum is used as a source of energy in operatingthe governor system,and in which a supplemental restraining means may be provided to enablethe vacuum itself to maintain the system operative (after manualinitiation by the vehicle-driver), but automatically renders the systeminoperative whenever the engine vacuum dissipates, for example, as aresult of turning off the engine ignition.

An important object of the present invention is to provide a speedregulator mechanism for an automotive vehicle, which regulator mechanismincludes a novel centrifugal flyweight device which is extremely simple,economical, reliable and includes speedsensing weight means which aresubstantially frictionless in speed-responsive movements; and whichcentrifugal flyweight device is novel, per se, and is thereforeapplicable in many applications other than for a speed regulator inautomotive vehicles.

The operation of vehicles on highway curves, when equipped with any ofthe above classified automotive speed control apparatus, whether theyinclude manual (hand-throttle) or automatic (governor) speedestablishing means, has been criticised sometimes from a safetystandpoint. When a vehicle approaches a curve (which is not suitablybanked) at a set speed of 65 mph for example, frequently the driver isso comfortable with his foot off the accelerator that he does not touchthe brake (when he should) to release the means holding the acceleratoror engine control means. As a result the vehicle traverses the curve ata speed higher than a safe value. This condition appears to be moreprevalent when the speed should be reduced only about 5 mph, forexample.

An important object of the present invention is to provide an automotivespeed control apparatus including a control system and an automaticspeed-regulating mechanism, in which curve sensing means are provided,when traversing highway curves in either a left or right direction, toeffect automatically a reduction of vehicle speed from the set speed asa function of an increase in highway curvature, and to automaticallyreturn the vehicle speed to the preset value as the curvature diminishesto a straight road.

Another object of the present invention is to provide in a controlsystem for automatic-throttle operation in an automotive vehicle, andincluding a speed governor mechanism, novel means to permit actuatingonly the control means of the engine independently of the acceleratorand linkage therefrom, but providing normal operative connection of theaccelerator and engine control means when the governor mechanism iseffectively inactivated.

A further object of the present invention is to provide a control systemfor an automatic-throttle mechanism in an automotive vehicle as recitedin the foregoing paragraphs in which all of the control functions oroperations may be accomplished by various movements of a single knob ordial, and to include tactile indicating means, if desired, so that onlythe sense of touch is required by the operator without removing hissight from the road.

Further objects and advantages of the invention will be apparent fromthe following description, taken in connection with the appendeddrawings, in which FIG. 1 is a somewhat diagrammatic view of a completeinstallation of one form of automotive speed control apparatus of thepresent invention mounted in an automotive vehicle and showing thecooperation of the control system and an automatic speed regulatingmechanism, and in which the selector means of the control system isshown in section taken along the line 1 l of FIG. 4;

FIG. 2 is a partial sectional view of the selector mechanism of thecontrol system for establishing the operating condition of the governormechanism as disclosed in FIG. 1 and taken along the line 2-2 of FIG. 3;

FIG. 3 is another partial sectional view of the selector mechanism shownin FIGS. 1 and 2 and taken along the lines 3-3 of FIG. 2;

FIG. 4 is still another partial sectional view of the selector mechanismof FIGS. 1-3 taken along the line 44 of FIG. 2;

FIG. 5 is an electric circuit showing the action of the restrainingmeans operated by a vehicle door;

FIGS. 6 and 7 are perspective views of important details of theflyweight device shown in FIG. 1;

FIG. 8 is a partial cross-sectional view of the centrifugal flyweightdevice of FIG. 1 taken along the line 8-8;

FIG. 9 is a partial sectional view of the brakeoperated release meansincluding throttle-responsive activating means as taken along the line9-9 of the valve unit FIG. 10 is a diagrammatic view of an alternateform of .restraining means operated by the vehicle seat;

FIG. 11 is a diagrammatic view of an alternate or supplemental form ofrestraining means operated by the vehicle transmission lever;

FIGS. 12-14 are partial sectional views of a supplemental form ofrestraining means operated by engine vacuum and modified from the formshown in FIGS. 1-4, and in which the portion shown in FIG. 12, asmodified, would be seen along the line l-1 of FIG. 4;

FIG. 15 is a fragmentary and partial sectional view of another form ofrestraining means operating as a modification of the speed governormechanism shown in FIG. 1 cooperating in part with the form shown inFIGS. 12-14;

2 FIG. 16 is afragmentary and partial sectional view of a modificationof the form of selective activating means shown in FIG. 9; and

FIGS. 17 and 18 are fragmentary sectional views of several modificationsof the form of the invention shown in FIG. 1, to provide an automaticreduction of vehicle speed on highway curves.

It is to be understood that the invention is not limited in itsapplication to the details of construction and arrangement of partsillustrated in the accompanying drawings, since the invention is capableof other embodiments and of being practiced or carried out in variousways. Also, it is to be understood that the phraseology or terminologyemployed herein is for the purpose of description and not of limitation.

It is also to be understood that the present invention may be used inany kind of highway or road vehicle such as for automobiles and trucks,and may control any kind of engine therein such as an internalcombustion gasoline engine or diesel engine, a gas turbine, etc.

,The governor mechanism disclosed herein has particular utility incombination with the selective control system of the present invention.However, the selective control system may also be used with any othersuitable speed governor mechanism or equivalent, or with any other kindof mechanism tending to correct throttle position in any desired manner.

The form of the invention illustrated by the automotive speed controlapparatus shown in FIG. 1 will first be explained from a constructionalstandpoint before discussing the operation. The speed governor orregulator mechanism will first be explained in its automatic operation,and then the control system therefor will be discussed. The variouscomponents illustrated in FIG. 1 are shown in working cooperationprimarily for ease of understanding and are not necessarily shown intrue proportion.

SPEED GOVERNOR MECHANISM The speed regulator mechanism illustrated inFIG. 1 includes two basic components or units, as follows: asensor-brain unit, generally indicated by the numeral and a servomotorunit, generally indicated by the numeral 7.

In FIG. 1 there is shown a conventional brake pedal 10 supported by anarm 11, and carburetor 12 in an engine intake passage or manifold 14 andincluding a control member such as a throttle 16 with a lever 18,operated by an accelerator 20 hingably connected to a floorboard 17through a shaft or link 21 all biased in their idle-speed direction byan idle spring 24 and a lever spring 26, to be discussed hereinafter.The lever 18 and throttle 16 are operated by the speed-regulatormechanism through override or lost-motion means, illustrated in FIG. 1as a ball-chain link 29 to enable actuation of lever 18 by theservo-motor 7. In the form shown, the accelerator linkage engages lever18 by means of a second override or lost-motion unit 35 having aU-shaped member or bracket 37 carried by the lower portion of lever 18and having holes to enable shaft 21 to slide therethrough. An abutment39 is secured to the shaft 21 to enable actuation of lever 18 by theaccelerator.

The override link means 29 is actuated by a pressure responsive memberof the servo-motor 7, such as a diaphragm 40 having atmospheric pressureon one side thereof in a chamber 42 and vacuum on the other side thereofin a chamber 44. The vacuum-derived force of diaphragm 40 is biased oropposed by a servo-spring 46 which tends to close the throttle 16 whenthe regulator is in operation. The vacuum in chamber 44 acting ondiaphragm 40 is modulated by a pilot valve 48 (illustrated as a ball),carried by a swingable arm 49 of the sensor-brain unit 5 supported forfrictionless modulating movements at one end thereof by hinge means,

such as a leaf spring member 50, which leaf member is rigidly mounted toa fixed portion of the sensor-brain unit by suitable means, as by ascrew.

The pilot-valve 48 controls a fluid circuit in which air from theatmosphere passes through a filter F into a chamber 52 and then flowsthrough an inlet orifice or restriction 54, and through a passage 55 inthe sensorbrain unit 5, through a conduit or passage 56 which is in opencommunication with chamber 44 (preferably made of synthetic rubbertubing), then through an outlet orifice or restriction 58 in a tube 59secured to a cover 60, and out through a conduit or passage 61subsequently to the intake manifold 14 without further restrictionduring operation of the governor mechanism by means to be discussedfurther. The passage 61 is preferably made of synthetic rubber tubing.

The pilot valve 48 may assume any suitable contour, but in the formshown, the ball valve is held in alignment by leaf spring 50, or otherhinge means, and is biased in a closing direction by a speeder-spring 62for cooperation with restriction 54 to vary the aperture thereof. Spring62 is preferably but not necessarily of variable rate, since the forcesproduced by the weight mechanism to be described vary as the square ofthe speed.

The pressure (vacuum) in passage 56 between the two restrictions 54 and58 is applied to diaphragm 40. A tapered re-set valve 64 may be providedto be suitably connected to diaphragm 40 and is effective upon movementsof the diaphragm and throttle 16 to vary the aperture at restriction 58as a function of the position of the throttle. The chain link 29 isconnected to diaphragm 40 by any suitable means, as by a ball in asocket.

The socket includes a threaded portion 66 cooperating with matingthreads of the valve 64. Adjustment of valve 64 by a screw slot 67changes its effective relationship with the throttle 16, to providespeed-droop control.

When the pilot valve 48 is held closed by speederspring 62,substantially the maximum available vacuum exists in conduit 56 andchamber 44. When the pilot valve progressively is moved from its seatedposition to its full open position, by means to be discussed, the vacuumin conduit 56 and chamber 44 is modulated and gradually reduces to avalue enabling full leftward travel of diaphragm 40 caused by spring 46.The maximum diaphragm vacuum obtainable in chamber 44 during regulatoroperation, such as 5 to 7 inches of mercury for example, is establishedwhen the diaphragm 40 overpowers the force of spring 46 to advancethrottle 16 until the vacuum reduces enough to balance the spring. Forthe same reason, the minimum manifold vacuum obtainable in the engineduring the regulator operation is substantially the same as this 9.maximum diaphragm vacuum. As valve 48 gradually opens to reduce thevacuum in chamber 44 from the maximum value, diaphragm 40 graduallymoves to the left as a function of the travel of valve 48 to the left,and conversely, as shown in FIG. 1.

A novel centrifugal flyweight mechanismhaving rolling weights providescentrifugal forces that vary as a function of vehicle (or engine) speed,which forces act on the pilot valve to cause speed-responsive movementsthereof as a result of changes in the centrifugal forces. The forcesproduced by the rolling weights are opposed and balanced by spring62which is'manually adjusted by axial movement of aspring retainer 76operated by a suitable shaft means inserted through a cover 77, such asaflexible shaft 80 controlled by the operator and slidable ina sheath81, to be discussed further. A bushing 82 is secured to cover 77 bysuitable means, as by staking, or is a part of cover 77. The sheath isinserted in the bore of the bushing, and secured, as by a screw.

Referring to FIGS. 1, 6, 7 "and 8, a housing 84 includes fixed portionsof a perimetrical surface, such as cylindrical surface SShaving spacesto accomodate a pair of radially movable portions such as the segments86 and 88 which comprise part of the cylindrical surface. Surfaceportion or segment 86 is suitably secured to arm 49 to effectspeed-responsive movements 1 thereof in a manner to be'described. Aplurality of rolling (or sliding) weights 90, such asballs or rollers asillustrated, are each connected by frictionless means (as by pivots) toa yoke member 92 having a knife-edge 92a. The yoke member is connectedfor frictionless radial movements at knife-edge 92a to an arm 94 of arotatable spider or impeller 96. The knife edges are fulcrummed at thecorners 94a of arms 94 to enable the weights to be rolled in a generallycircular path by impeller 96 which is suitably secured to a rotatingshaft 98 for rotation thereby; the shaft is driven by the engine ortransmission and in present vehicles usually comprises the flexiblespeedometer shaft of an automotive vehicle. The radial centrifugal forceof each weight as it rolls (or slides) across the surface portion 86 istransmitted to arm 49 and balanced by spring 62 to position valve 48,which opens as the shaft speed increases, and conversely.

The speed-regulating action of the governor mechanism described thus faris as follows: When the rotary speed of the vehicle increases, thecentrifugal force produced by the roller-weights urges the pilot valve48 to the left biased by spring 62 to open the restriction 54 graduallyas the speed increases. This action decreases the vacuum in chamber 44in a modulated manner previously described, so that spring 46 movesdiaphragm 40 to the left, as viewed in FIG. 1, which enables spring 26to retard throttle 16 tending to restore the regulated speed. When thevehicle (or engine) speed decreases, the regulating action is thereverse of that above de scribed, to advance the control means andrestore or maintain the governed speed.

FIGS. 6 and 7 are enlarged perspective views of the yoke and spider arm,respectively. The yoke includes an extension 92b which projects throughslot 94b in arm 94 to maintain the yokes in position to clear the endwall 84a of housing 84 and a cover piece 100 as shown best in FIG. 8.Also, for best results, the entrance radius of portion 86 is slightlygreater than the radius of surface 85, whereas the trailing radius ofsurface 86 is slightly less than the radius of surface 85. In order toenable a smooth and continuous transfer of the rolling weights from thefixed surfaces to the radially movable surface 86, the ends of eachsurface are suitably rounded or contoured for this purpose. In FIG. 8,it can be seen that the movable surface portion 86 (as well as portion88 to be discussed) completely clears end wall 84a and cover 100. Sincethe swingable arm 49 and its leaf spring 50 are frictionless, the speedresponsive movements of all parts moved radially by the rolling weightsare completely frictionless. An important characteristic of thisflyweight inventive combination is that the rolling weights arefrictionless in radial speed-change-responsive movements. This is truebecause all rolling friction occurs in a direction transverse to theradial direction of movement and has no component in said radialdirection. The only radial (angular) movements of the weights and yoke92 is controlled at the knife-edge connection of elements 92a and 94a,which connection is completely frictionless in its radialspeed-responsive movements. Hence, this novel centrifugal weightmechanism is completely frictionless, and has many useful applicationsother than for automotive speed regulating systems. I-Iowever, thiscentrifugal weight mechanism is extremely simple and can operate at lowdriving torques so that the speedometer shaft is not overloaded which isan important consideration. Accordingly, while the weight mechanism hasseparate utility, per se, ithas particular utility in a combination ofelements comprising an automotive speedregulating mechanism, and moreparticularly in combination with the remaining mechanism disclosedherein because of its overall utility and simplicity.

When the centrifugal weight mechanism is used as part of an automotivespeed regulator, as illustrated in FIG. 1, it is preferable for thesurface portion or segment 86 to be mounted toward the rear of thevehicle. Then, when the vehicle is accelerated automatically, theadditional inertia forces of the weights cause valve 48 to open earlywhich effects operation of the regulator mechanism before the stablepreset speed is attained. This action results in a soft" cut-in of theregulator mechanism.

As illustrated in FIGS. 1, 6 and particularly FIG. 8, the rollingweights are retained by pivots mounted in conical recesses in the armsof yoke 92. The arms have narrowed sections 920 to provide a springaction for enabling the weights to be snapped in place. As analternative, the weights may be secured to the yoke wherein the weightsslide instead of roll on the cylindrical surface; however, with thisconstruction the elements must be made of low friction materials tominimize the frictional drag on the speedometer shaft. When the vehiclemoves in a backward direction, the rotary speed of impeller 96 is verylow and the arms 94 move the weights in a reverse direction. Althoughthe rolling weights are illustrated as being pushed by the yokes 92 inregulator operation, they could be arranged to be pulled by the impellerarms 94, if desired, to provide the same rolling action withoutdeparting from the spirit of the invention.

The diaphragm 40 and spring 46 are selected to hold the throttle at itsmaximum opening at the highest practical diaphragm vacuum such as 5-7inches of mercury in passage 56 and chamber 44. As previously described,the necessary diaphragm vacuum is determined by the force of spring 46and the size of diamph, the control of the regulator mechanism isdetermined by the pilot valve 48 and by selector control means, to bediscussed. Whenever the vehicle speed falls below the illustrated speedof 15 mph regardless of the reason, the regulator mechanism cannot beactivated in any manner. I

When the terms pressure or vacuum are used herein, they both refer to apressure differential. Positive pressure is the difference between apostatmospheric absolute pressure and the atmospheric pressure. Vacuumisthe difference between a subvacuum must be chosen to compromise theseopposing factors. As the pilot valve 48 opens when the manifold vacuumis above the critical value, the diaphragm vacuum gradually reduces fromits maximum as above noted by movement of the pilot valve to an amountwhich enables spring 46 to retard throttle 16 as required. Hence thediaphragm 40 will not start'moving to'the left, as viewed in FIG. 1,until the vacuum in chamber 44 is reduced by movement of pilot .valve 48to be less than the value of this critical vacuum. Thus, if the spring46 is selected to enable the governor mechanism to maintain the governedspeed at inches of mercury, for example, the size of diaphragm 40 wouldcause it to start moving at a lesser vacuum, such as 4 54; inches ofmercury, for example, when the pilot valve starts to open. The totalleftward travel of diaphragm 40 to close throttle 16 might be effectedwhen the pilot valve opens enough to produce a still lesser vacuum, suchas 2 k inches of mercury, forexample, determined by the rate of spring46. The foregoing concept is utilized in a novel manner to facilitateautomatic acceleration at a limited rate, to be discussed furtherhereinafter.

When the operator accelerates the vehicle manually at a moderate ratewith the throttle producing a higher manifold vacuum, such as 12-14inches of mercury, for example, this higher vacuum acts on the exposedportion of the pilot valve and might delay its opening slightly to ahigher speed than selected. A relief or regulator valve 104 which isbiased by a light spring 106 is set to open at a manifold vacuum ofabout 6-7 inches of mercury, with the foregoing example, forlimiting'the vacuum in passage 56 and chamber 44 to this value bybleeding air thereto. This vacuum is high enough to hold diaphragm 40 inits extreme right position until the pilot valve opens.

The centrifugal weight mechanism as disclosed herein includes means topreclude operation of the speed regulator mechanism until the vehiclehas actually attained a low predetermined speed, such as -20 mph forexample. As illustrated herein, the cut-out mechanism comprises a valve110 cooperating with an orifice 112 to bleed air into passages 55, 56 inparallel with the pilot valve 48. The bleed valve, illustrated as rubberor the like, is secured to the radially movable portion or segment 88,which is supported for frictionless swingable movements by a leaf spring114,, or equivalent hinge means. The assembly of segment 88, valve 110and hinge 114 is biased in an opening direction by a light spring 116 inopposition to the force of weights 90 rolling on portion 88. When thevehicle is at rest, spring 116 holds valve 110 open to bleed air intopassages 55, 56 and chamber 44 to render the regulator mechanisminoperable. When the vehicle attains a speed determined by spring 116,such as 15 mph, the weights 90 close valve 110; then at all speeds abovel5 atmospheric absolute pressure and the atmospheric pressure.

SELECTIVE CONTROL SYSTEM Automatic throttle or speed control devices nowin use are so arranged that the vehicle must actually attain the setspeed before the regulating mechanism can be activated. It is myintention in the speed-regulatingmechanism of the present invention toprovide safe automatic acceleration after the device is safely engagedor activated at any speed below the set speed at which time the driverremoves his foot from the accelerator after hearing an audible signal;and then the vehicle automatically accelerates slowly or moderately fromthe engaged speed to the present speed. Hence, the main utility of thecontrol systems of the present invention is to effect such automaticactivation only after a partial and temporary advance of the throttle oraccelerator. Then when the throttle is deliberately and selectivelyopened temporarily by the vehicle-driver (while the vehicle attains aspeed somewhat less than the preselected speed), the speed regulatordevice is activated and automatically accelerates the vehicle moderatelyto the preset speed. The audible signal is produced upon such activationto indicate that the drivers foot can be removed from the accelerator.

In utilizing the present invention as an automatic throttle for turnpikedriving, I provide a control system operable in one form only after thedriver enters the vehicle and the doors are closed which enables thedevice to be initially activated by the driver. In the form shown, suchcontrol system includes a valve unit having an activation valve operatedby movement of the brake pedal to shut off or open the source vacuum tothe speed regulator; and as part of the control means I further provideautomatic engagement or activation means operated as a function ofmovement of the accelerator pedal or throttle which opens the valve toautomatically re-activate the regulator device after a partial andtemporary advancement of the accelerator pedal. In the forms shownherein, such automatic activation means includes a diaphragm exposed tomanifold vacuum which opens the activation valve after the throttleopens enough to reduce the manifold vacuum sufficiently to cause suchautomatic activation or engagement.

My control system, in one form of the invention, may include a secondshut-off safety valve which is initially opened by a first dpression ofthe brake pedal and thereafter is held open by manifold vacuum; but thesafety shut-off valve is automatically closed whenever the vacuumdissipates for any reason. The safety valve is again openedautomatically only upon the first brake actuation and providing manifoldvacuum again exists in the supply tube. I also include in my controlsystem selector valve means in the vacuum source conduit,

which valve is manually and selectively opened by the.

driver, but in one form of the invention is automatically closed byrestraining means operated by the vehicle door, or by other suitablerestraining means initiated upon activation of a driver-operated movableelement of the vehicle which detects a change of drivers. Manuallyoperated (safety) means are associated with the restraining means forenabling manual operation of the restraining means at any time to renderthe speed control device inoperative, and precludes operation of therestraining means until it is operated deliberately by the driver. Thus,in one form of my control system, the device is automatically renderedinoperative by restraining means operable incident to the driverleavingthe vehicle and can only be set for activation by the driverselectively and deliberately after each time he closes the door (and ifhe moves the transmission lever into drive position if this factor isprovided); and thereaf ter the device is automatically activated finallyupon a deliberate and temporary advancement of the accelerator until anaudible signal is heard following each temporary inactivation of thedevice by normal operation of the brake pedal.

The control system, in the form of the invention illustrated herein,includes two main components for controlling the transfer of vacuum tothe tube 61 from another tube or conduit 120 (preferably made ofsynthetic rubber) to supply vacuum'from the manifold 14 as a source ofenergy or power to the servo-mechanism in the governor portion of thesystem. The selective valve means is a main component of the controlsystem and comprises a selector mechanism or unit, generally indicatedby the numeral 122. The selector unit of the present invention includesa manually-operated member or means movable upon operation at least onceby the vehicle-driver to open a valve for transferring or communicatingthe full vacuum from the manifold 14 through tube 120 and another tube61' to the tube 61. The vacuum is maintained in these supply tubes bythe manually operated member at least when the vehicle driver remains inthe vehicle or unless the manuallyoperated member is deliberatelyreturned to its inoperative position by the driver thereby shutting offthe vacuum to preclude transfer thereof to the servo-motor. If theoperator fails to move the manually operated means to shut off thevalve, automatic restraining means are provided in which the selectivemovement of an element of the vehicle, such as opening a door,automatically causes movement of the manual means to shut off the valve;then the operator again must consciously move the manual meansdeliberately to enable activation of the system.

Referring to FIGS. 1-4, the form of the selector unit illustrated hereinincludes a mounting bracket 124 suitably secured to a fixed portion ofthe vehicle in the drivers compartment, such as by screws fastened tothe underside of the instrument panel 126. The bracket includes adownturned portion or plate 128 which is secured, as by screws, to acover or cup member 130 to form a chamber 132. A bushing 134 is suitablysecured to plate 128, as by staking or soldering, and includes a bore toguide and support a shaft 136 for axial movements in relation to thebushing. The shaft extends through chamber 132 and also through aclearance hole in cover 130 and carries a pinion gear 138 suitablysecured to a portion of the shaft 136a having a reduced diameter toreceive the gear.

One or more air vents, illustrated as holes 140, are provided in coverradially equidistant from shaft 136. The holes are covered and closed bya disc-valve 142 (FIGS. 2 and 3) .inserted on the small diameter 136a ofshaft 136 and retained by the gear between it and the step in shaft 136.

The cover 130 includes two hose nipples 144 and 146 to receive tubes 120and 61', respectively. Nipple 144 is selectively covered or openedunrestrictedly by a valve-body or restrictor 154 supported by a stem orshaft 155 made of any suitable rod or pin (FIG. 1). The stem is securedto and supported by plate 128 by suitable means, as by riveting,staking, soldering, etc., so'

that the stem is restrained from axial movements. The valve body 154 hassuitably flanged ends and slides with small clearance on stem 155 foraxial movements in relation thereto for purposes to be described. Anactuating disc 156 is suitably secured to shaft 136 and extends betweenthe flanged ends of valve body 154 to produce axial movements thereofupon axial movements of the shaft 136, while enabling rotation of theshaft.

Any suitable speed-establishing means may be provided. In the forms ofthe invention illustrated herein, such means includes a knob 160 havinga single tactile Braille indicator 161 on its periphery is secured toshaft 136, as by a set screw (FIG. 2), to facilitate axial and rotarymovements of the shaft as required, to be explained.

Referring to FIGS. 2, 3 and 4, means are provided in the selector unitto translate rotary movements of the knob to axial movements of theflexible shaft 80 in any desired ratio. In the example shown herein,such means comprise a circular rack-piece 162 connected to the mountingbracket 124 for freely moving angular movements by a suitable hinge pin164. A conventional swivel 166, as used for carburetors, is hingablysecured to rack-piece 162; and flexible shaft 80 is inserted through theswivel and retained by the usual screw provided with the swivel, asshown. The sheath 81 is secured to the mounting bracket 124 by a clamp167 fastened by suitable means, as by a screw. In this manner, angularmovements of the rack-piece produce axial movements of the flexibleshaft.

Thus, the knob 160 is revolved by the driver to select the governedspeed, by causing such angular movements of the rack-piece to move shaft80 and vary the force of speeder spring 62 as desired. A pair of stops168 are secured to (or are a part of) the mounting bracket 124 to limitthe rotary movement of the rackpiece so that the knob 160 can be rotatedonly one complete turn. The same result may be achieved by any otherequivalent stop means, such as by limiting the shaft itself. The theentire speed range of the speed regulator mechanism is calibrated tofall within this one turn; this may be accomplished in the presentinvention by varying the rate of spring 62 and/or varying the radialposition of the swivel 166 as desired. The driver memorizes the speedscorresponding to various clock positions of the tactile indicator 161.Thereafter, he rotates the knob by feeling the tactile indicator toestablish the correct clock" position for the desired speed. In thismanner the driver can select the governed speed at any time withoutremoving his sight from the road. The tactile indicator in FIGS. 2 and 3is shown positioned at six oclock with the gear 138 in the middle of itstravel with respect to the rack-piece 162.

In FIG. 1, the tactile indicator is shown in its twelve oclock positionwhen the rack-piece contacts either of its stops 168. The rack-piece 162includes an extension 162a prebent to provide a friction force whenretained by hinge pin 164, to maintain knob 160 in any set rotaryposition. A solenoid 147 is secured to a downturned portion 124a ofbracket 124 and includes an armature 148 having a link 149 connected toextension 136a but adapted to enable rotation of shaft 136. Referring toFIG. 5, the circuit for solenoid 147 includes the vehicle battery 150 inseries with the parallel connection of the vehicle-doors, such as doors151 and 151', to control the usual spring-biased switches 152 and 152,respectively. The vehicle door switches are in series with the usualdome light 153 which is provided in most automotive vehicles.

The valves 154 and 142 of the selector mechanism may be replaced by anyequivalent valve means such as a slide valve, or a spool valve slidingin a bore to control ports, etc., without changing the spirit of theinvention.

The selective control system also includes means to enable safeautomatic acceleration (sometimes called, Resume Speed) in a mannerwhich is initiated from a condition of' normal driving, since thedrivers foot initially must be on the accelerator. In the form of theinvention disclosed in FIG. 9, the second component of the selectivecontrol system as shown in FIGS. 1 and 9 comprises a valve unit 170 in ahousing 172 which is secured to the steering post 174 (or some otherfixed portion of the vehicle) by a bracket 176. The housing includeshose nipples 178 and 180 to receive tubes 61 and 61', respectively (asshown only in FIG. 9), for transferring manifold vacuum from theselector unit to the servo-motor. Referring particularly to FIG. 9, thevalve unit 170 includes a diaphragm 182 clamped between housing 172 anda cover 184 by suitable means, as by screws, to form a pair of chambers186 and 188. A brake-operated activation valve 190 includes a flangeportion secured to diaphragm 182 by bonding, or by a clamping action ofa disc 192 secured by rivets, or the like. Valve 190 includes a sealingportion or 'member 194 adapted to open or close a port 196 communicatingwith vacuum tube 61 and tube 61. Valve 190 includes a stem 198 slidablein a bore in cover 184 to enable axial movements of the valve whilesealing chamber 188. The valve stem includes an internal air passage 200which always connects chamber 188 with only the upper end of valve 190,as shown in FIG. 9.

A bar 202 is hinged to a fixed support 204 to enable swingable movementsof the bar for actuating valve 190 biased by a spring 206 acting on thevalve. A firm leaf spring actuator 208 is secured to bar 202, as byrivets, and is mounted at an angle to the bar to contact the engine-sideof the brake arm in its idle position, as shown in FIG. 9. The actuator208 is sufficiently firm that bar 202 normally moves as though it were arigid portion of the actuator. Whenever the brake pedal is depressed Itis to be understood that the valve unit 170 may be used in other speedcontrol systems without the selector unit 122 and/or without the disc222, valve 216 and spring 228. it acts on a suitable angle-portion ofactuator 208 to cause swingable movements of bar 202 and axial movementsof valve 190. If the valve unit 170 is mounted too close to the brakearm, valve 190 would seat on port 196 before actuator 208 moves to theside of the brake arm when it is fully depressed. In this event, theleaf spring 208 merely bends sufficiently to enable the full travel ofarm 11 since the spring force of actuator 208 is much greater than theforce of spring 206. Als o, a bleed-valve 210 is biased by a spring 212and normally closes an atmospheric air vent to chamber 188. The valve210 includes a stem 214 actuated by the bar 202 to open the bleed valvewhenever the brake pedal is depressed.

If desired for extra safety, the valve unit 170 may include a safetyshut-off valve 216which is adapted to open or close a second port 218 inseries with valve 192 and itsport 196. Valve 216, as exemplified in FIG.9, comprises a ball supported by a stem 220 secured to a pressuresensitive member illustrated as a movable disc 222. The disc seats on asurface of housing 172 to form a chamber 224 which communicatesunrestrictedly with chamber 186 through a passage 226. Hence, the disc222 comprises a movable pressure-sensitive wall of chamber 224 and isbiased in a direction to'open the chamber to atmosphere by a spring 228.The disc 222 includes a lost-motion extension 230 which projects throughan aperture in bar 202 to cooperate therewith in a manner to bedescribed. The area of the disc and force of spring 228 are selected sothat a vacuum of only about 1 to l A inch of mercury is sufficient tohold disc 222 closed and valve 216 open.

The overall operation of the control system will now be described,assuming the driver has entered the vehicle and started the engine withthe knob 160 in its off" position, in which all parts connected theretoare in their rightward position as would be viewed in FIG. 3. In thiscondition, the valve body shuts off vacuum from tube so that atmosphericpressure exists in tube 61', tube 61 and in the valve unit 170. At thistime, referring to FIG. 9, valve 190 is held open by spring 206 sincethe pressures in chambers 186 and 188 are atmospheric; also, the spring228 forces disc 222 to open chamber 224 to the atmosphere and to holdvalve 216 on port 218. When the driver wants to activate the speedcontrol mechanism in the form shown, such as when the vehicle is inmotion, he must perform at least three deliberate and conscious steps toproduce such activation. First, the knob 160 is pulled out into its on"position at any desired vehicle speed, so that all parts connectedthereto stand in their leftward position, as shown in FIGS. 1 and 2. Atthis time, the left end of gear 138 acts on disc-valve 142 to close theair vents and simultaneously open valve body 154 to transmit the fullundiminished manifold vacuum to chamber 132, tube 61' up to valve 216,which is still closed.

If value 216 and disc 222 are provided, the second deliberate action bythe driver comprises the first depression of the brake pedal afterpulling knob to its on position. At this first brake-actuation, the bar202 closes chamber 224 while opening valve 216, so that manifold vacuumacts on disc 222 to maintain same in its closed position with valve 216open as long as vacuum is supplied in tube 61'. This same brake-actuatedmovement of bar 202 on stem 198 to close valve on port 196. This actionalso opens the bleed valve 210 so that atmospheric pressure exists inchamber 188, air

passage200, tube 61, chamber 44 and passages 56 and 55. At the sametime, the full manifold vacuum is transmitted to chamber 186 and on theupper side of diaphragm 182 (as seen in FIG. 9) to overpower spring 206and hold valve 190 tightly closed against the port 196. This actionrenders the speed control device inac- .acceleration is desired to apreviously set or preset speed of 65 mph, for example, the drivernormally accelerates the vehicle to a moderate speed such as -20 mph sothat valve 110 is closed. Then the driver smoothly but firmly (in adeliberate selective operation) depresses the accelerator to temporarilyopen throttle 16 and reduce the manifold vacuum sufficiently to enablespring 206 to overpower the vacuum force of diaphragm 182. This actionopens valve 190 which enables the manifold vacuum to be transmittedthrough tube 61 to the speed-regulator mechanism for activation thereof.At this time the manifold vacuum is applied to both sides of diaphragm182 so that spring 206 thereafter holds valve 190 open at all subsequentvalues of manifold vacuum. The driver can now remove his foot from theaccelerator pedal (at a vehicle speed of about 20 mph in this example),and the vacuum acts on diaphragm 40 to open the throttle which causesautomatic acceleration from this lower speed. When the diaphragm isactivated by this vacuum, a leaf spring clicker 232 carried by thediaphragm moves past the cover 41 to produce an audible click signal foradvising the driver that the regulator mechanism is activated. Thevehicle is then accelerated automatically up to the preselectedregulated speed established previously by pulling knob 160 when set toprovide the desired speed. When the preset governed speed is attained,the pilot valve 48 is automatically opened by the roller weights 90 tobleed air into chamber 44 through conduits 55 and 56; and thereafter thegovernor mechanism automatically maintains this preselected speed in thespeed-regulating action at all loads, as previously described. Theoperator can override the governor action at any time by depressing theaccelerator enabled bythe lost-motion chain-link means 29, and when heremoves his foot from the accelerator the vehicle speed returns to thepreselected governed value- The value of manifold vacuum that causesvalve 190 to open upon advancing the accelerator, as described in thepreceding paragraph, is established by the force of spring 206' (for agiven size of diaphragm). This value of manifold vacuum can beestablished initially in a very small range, but I have found values of3.5 to 5 inches of mercury to be satisfactory. If this vacuum is set ata higher value, such as 7-8 inches of mercury, the accelerator is notdepressed as much as for a lower vacuum setting.

It is important to realize that this automatic activation is effectedprimarily as a function of throttle position substantially independentof engine speed, because manifold vacuum predominently is a function ofthrottle position, particularly near road-load operation. If the driverdesires to accelerate the vehicle manually, for example when he might befollowing other vehicles temporarily, he depresses the acceleratormoderately -that is, only to positions providing valuesof vacuum abovethat for releasing valve 190. I have that by this means, the driveractually can exceed the preset speed without activating the regulatormechanism. This is very useful when following slow variable-speedtraffic.

When the traffic clears, the driver merely advances the accelerator asabove described until he hears the sound of clicker spring 232, and heagain removes his foot from the accelerator pedal. Another click signalis produced when the stem 198 strikes bar 202, which signal alsoindicates that activation has occurred.

When the brake pedal is depressed to retard vehicle speed, valve 190closes to shut off all vacuum to chamber 44, and then is held closed bymanifold vacuum as previously explained. Instantly the spring 46 movesdiaphragm 40 to its extreme leftward position out of the way of normalaccelerator movement, so that spring 26 moves the throttle to its idleposition. At this time, valve 48 is closed and valve is again openedafter the vehicle speed reduces to zero. This brake release does notaffect valve 216 which remains open since the bar 202 merely slides onthe lost-motion stem 230. Since valve 154 remains open, the fullmanifold vacuum is maintained in chamber 132 if a door is not opened, sothatthe selector mechanism is unaffected by depressing the brake pedal.When the brake pedal is released and valve 190 is held closed bydiaphragm 182, vacuum is not transmitted through tube 61 to orifree 58.In addition while the vehicle is at rest, the governor mechanism ismaintained inactive because of the air-bleed past valve 110 aspreviously explained. Thus, the brake-release means renders the speedcontrol device only inactive since it remains ready to be activated bymanual selective activation; the speed control device is never renderedinoperative or locked-out by the brake-release means, as disclosedherein.

In order to re-activate the governor mechanism, it is not necessary toreset knob in any way. It is only necessary for the driver toselectively advance throttle 16 (after the vehicle attains a speed of 515 mph which causes valve 110 to close) to a position that lowersmanifold vacuum to about 4 inches of mercury. This causes valve 190 tobe opened by spring 206 so that vacuum is transmitted instantly to theorifice 58, and the diaphragm 40 again opens the throttle toautomatically accelerate the vehicle to the preset speed, as describedabove.

Referring to FIG. 1, if desired, the valve unit may be installed in tube120 between the intake manifold and the selector unit 122. In thisevent, after the engine is started and before knob 160 is pulled out,the valve is closed on port 196 at the first normal brake actuation, sothat the brake pedal does not have to be depressed once after pullingout knob 160. However, the installation shown in FIG. 1 may bepreferable from a safety standpoint because an extra conscious effort isrequired. of the driver after he deliberately pulls knob 160.

If the disc 222 is made smaller to release at 2 to 3 inches of mercury,for example, the regulator will be rendered inoperable automaticallyeach time the accelerator is depressed to wide-open-throttle position.This calibration can be used, if desired, to discourage hot rod"acceleration.

It is also important to realize that the combination of the disc 222 andvalve 216 can be used by itself in any automotive speed regulatormechanism having source of pressure or vacuum to power the device. Inthis combination, the safety shut-off valve with the disc 222 acts as asafety mechanism to lock out the regulator mechanism after the manifoldvacuum dissipates; and requires a first actuation of the brake pedalafter the engine is started to enable activation of the regulatormechanism.

Restraining means are provided to automatically render the regulatormechanism inoperative to preclude any dangerous situation, for examplewhenever there is a change of drivers. The main purpose of therestraining means is to enable the use of the automatic activation (orengagement) means with subsequent automatic acceleration without adangerous surprise factor whenever there is a change of drivers, or evenif the same driver leaves the vehicle for extended periods and mightforget that the devie is ready to be engaged. For example, without therestrianing means and associated manual safety means, but with automaticactivation means and automatic acceleration provided, if another driverenters the vehicle while the engine is idling, he might be surprised notknowning that the speed regulator is engaged, or worse, not even beaware that such a device exists or is on the vehicle. The restrainingmeans, in one of the several forms disclosed herein, automaticallycauses the speed control device to be rendered inoperative incident tonormal selective operation of an element of the vehicle by the driver,which selective operation normally occurs whenever there is a change indrivers (while the vehicle would be at rest) so that the desired resultis accomplished.

In the forms of the invention illustrated in FIGS. 1-5 and -14, therestraining means includes or is operated by a selective vehicleelementtsuch as a vehicle door, or by movementof the drivers seat,and/or transmission selector means. The terms restraining means andselective vehicle element when used in the claims relate to thepotentially dangerous condition when there is a driver-change with thespeed-control device set for automatic activation, which in the formsshown in FIGS. 1-5 occurs of course only after the vehicle is brought torest. The control device is rendered inoperative incident to operationby the vehicle-driver of an element which is a part of the vehicle, andis operable at his selection normally or usually when the vehicle isimmobile, and accompanies a change in drivers or when one driver leavesthe vehicle for a while and returns later thereto.

The vehicle-element, illustrated herein is selective by the driver inthe sense that in normal operation of the vehicle, it is the driverschoice or selection to open a door, for example; and the speed-controldevice is automatically rendered inoperative incident to and as a resultof this selective movement of this vehicleelement, which selectivemovement normally accompanies a change in drivers as desired. In theforegoing example, normal operation of the vehicle is intended to coverany normal driver operation required between the times when the vehiclestands alone without a driver both before and after it is driven; andany element necessary to be operated by the driver selectively toperform such driver-operation between these times may be utilized if itqualifies broadly as above described.

The particular examples of restraining means illustrated herein comprisea combination including manually operated shut-off means. Therefore itis first necessary to consider the manual shut-off action of theselector unit 122 described above, as shown in FIGS. 1 -4. If at anytime, the driver wishes to render the automatic throttle or governoraction inoperative manually, he pushes knob 160 in" to the right, asviewed herein. As

shown in FIGS. l-3, the shaft 136 moves disc valve 142 to open the ventsand simultaneously the valve body 154 is moved to cover the inlet ofnipple 144. At this instant, the knob is in the position shown in FIG.3. The vacuum instantly dissipates from chamber 132, tubes 61, 61, 56and chamber 44, and diaphragm 40 is moved to the left out of operationas previously described. At the same time, the dissipation of vacuum ondisc 222 enables spring 228 to open the disc and close valve 216; thisaction exposes chamber 44 and passages 61, 55 and 56 to atmosphericpressure regardless of any other factors. The vacuum is cancelled untilknob is pulled out and valve 216 is forced open and held open by disc222 after the engine is started and the brake pedal is again depressedonce. Hence, in order to set the speed regulator mechanism ready foroperation, the vehicle-driver must again deliberately pull knob 160 outinto the position shown in FIG. 1. If this is performed while thevehicle is being driven, the driver can activate the automatic regulatoras described above, but only after depressing the brake pedal once.

Now consider the action of the restraining'means illustrated in FIGS. 1,2 and 5. Whenever a vehicle-door 151 is opened for any reason, such asproduced by a change of drivers, the door switch 152 closes whichenergizes solenoid 147 and the usual dome light 153', this action causesarmature 148 to pull shaft 136 to the right, as shown in FIG. 1, whichinstantly shuts off all vacuum in chamber 132 and tube 61 in the samemanner as described above-for the manual shutoff when shaft 136 is movedby pressing knob 160 to the right. Also, as above described, the vacuumin the valve unit dissipates so that valve 216 is closed. Any new drivermust deliberately and consciously pull knob 160 to enable subsequentactivation of the regulator mechanism by depressing the brake pedalonce, and thereafter advancing the throttle until clicker 232 is heard.Then the foot can be removed from the accelerator and the vehicle willautomatically accelerate .to and maintain the preset speed, until thebrake pedal is depressed, or the knob 160 is pushed in, or the door 151is opened upon leaving the vehicle;

An alternate or supplemental restraining means is also disclosed inFIG. 1. In this form of restraining means a cam 234 is caused to revolvewhen the usual transmission selector shaft 235 rotates when moving thetransmission selector member from one position to another. In drive"position, the cam holds a valve 236 in a position to close a port 237 ofpassage 56. The valve is supported by a leaf spring 238 which is prebentto bias the valve open against the cam. When the transmission leverstands in drive position with valve 236 closed, the regulator mechanismoperates in a normal manner. Whenever the transmission selector lever ismoved out of drive position, valve 236 opens which bleeds in enough airto render the regulator mechanism inoperable until the selector memberis again moved into drive position.

The door operated restraining means is believed preferable with the formof the invention illustrated in FIG. 1 because it always detects achange in drivers. While a transmission operated restraining meansusually detects a change in drivers, sometimes a driver will stop thevehicle and leave the car with the engine idling and with the parkingbrake locked while the transmission lever remains in drive position. Inthis instance the transmission-operated restraining means will notdetect a change in drivers. Also, with the door-operated restrainingmeans, the driver must consciously pull knob 160after entering thevehicle and closing the door, The transmission operated restrainingmeans does not affect knob 160, and the regulator device is operableafter the transmission lever is moved into drive posi tion. Hence, thisrestraining means may beused to supplement the door-operated restrainingmeans if the extra expense is justified.

A characteristic of manifold vacuum, as discussed previously, isutilized to enable relatively slow automatic-acceleration followingsuch. automatic activation or engagement at a speed less than thegoverned speed. In all carbureted engines, the manifold vacuum reducesfrom about 19 inches of mercury at no-load to about one inch of mercuryat full-load as the throttle is opened. Such automatic acceleration isaccomplished by the device shown in FIG. 1, according to the presentinvention, by selecting the spring 46. so that the diaphragm vacuum inchamber 44 is never more than a preselected value, such as or 6 inchesof-mercury for example, which is a minimum for the manifold vacuum inthis instance. As previously explained the throttle opening at theminimum manifold vacuum corresponding to this maximum diaphragm vacuumrestricts the acceleration rate sufficiently to enable safe automaticacceleration. If the spring 46 is selected to provide a working(maximum)diaphragm vacuum of 8-9 inches of mercury (or higher),theacceleration rate is even slower after automatic-activation. However,this desirable result is accomplished at the expense of reducing furtherthe engine power at which the governed speed can be maintained.

It is important to appreciate that the parts in the vacuum supplycircuit (such as the passage in hose nipple 144, valve body 154, valveunit 170 and the tubes 120, 61' and 61) offer substantially noresistance or lineloss with all air-flows regardless of the openings ofvalves 64, 48 and 104. The only intended restrictions during normalspeed governor operation are at orifices 54 and 58, operating asdescribed in cooperation with valves 48 and 64, respectively. The airbleed itself is provided primarily to enable pilot valve 48 to controlpressure. 7

In the form of control system shown in FIG. 1, a double-abutment ordouble-override" linkage mechanism is provided. With this system,constructed as described above, when the governor override means 29operates throttle 16, as in FIG. 1, the accelerator override 35 enablesthe accelerator and its entire linkage (elements 20 and 21) to be biasedby spring 24 to stand in their idle position. Since the friction andinertia of the accelerator and its linkage does not have to beoverpowered by the speed governor mechanism, the size of servo-motor 7can be substantially reduced. A smaller servo-motor will respond faster,since in the form shown in FIG. 1, for example, less air must bedisplaced. Any servo-motor, regardless of the type of energy usedtherein, can be made to respond faster by reducing its size providingthe required forces are reduced. With a faster response, a speedgovernor mechanism is more stable without hunting. An optional advantageof the double-abutment system is to maintain the size of theservo-motor, but select spring 46 to operate at much lower manifoldvacuum; then the regulator maintains the set speed at a higher enginepower. If the lost-motion unit 35 is replaced by a pin connection, thendiaphragm 40 must operate link 21 and accelerator 20 in itsspeed-regulating movements.

I have observed in my own driving of speed control devices that whentraversing highway curves, there is a tendency to continue at the presetspeed even if the rate ought to be reduced 5 to 10 mph for safetypurposes. Several means are disclosed herein to sense the radius of roador highway curvature and automatically reduce the speed temporarily asrequired on such highway curves. One form of such curve compensationmeans, as disclosed in FIG. 1, comprises a weight 240 secured to a plate242 pivoted for angular movements to the left or right of the directionof the vehicle (viewed from above in FIG. I). A pair of links 244 and246 have diametrically opposite lost-motion connections with plate 242.The links 244 and 246 are hingably connected to arms 248 and 250,respectively, which in turn are hinged to pins secured to the walls ofan extension cover 77a. One arm includes a pin 252 cooperating with aslot of the other arm and is connected to a spring 254 attached to theswingable arm 49. Spring 254 is very light in relation to speeder spring62 so that the movement of arm 248 only varies the regulated speed asmall amount.

The curve compensation device operates as follows during automaticthrottle operation: On straight roads, the weight is maintained in itscentral position by the force of spring 254. In a right curve, weight240 moves upwardly (FIG. 1) which pulls arm 250 and extends spring 254an amount dependent on the radius of highway curvature; at this time,arm 248 and link 244 are carried along in a lost-motion action. Theextension of spring 254 causes valve 48 to open slightly which reducesthe regulated speed such as 5 to 10 mph; a greater highway curvaturecauses a greater temporary speed reduction. As the highway straightensout, the weight 240 gradually returns to its central position togradually restore the preset governed speed. When the highway curves tothe drivers left, the reverse action occurs; weight 240 moves to theright because of centrifugal force (downwardly in FIG. 1) which pullslink 244 and arm 248 to extend spring 254 an amount dependent on theradius of highway curvature; arm 250 and link 246 are carried in alost-motion action. The speed is temporarily reduced by extending spring254, and thepreset speed is restored as the highway straightens out.

The curve-compensation means provides another safety factor in additionto the actual automatic reduction of speed in curves. This second safetyfactor is that the periodic and automatic change in speeds tends toreduce the possibility of so-called highway-hypnosis.

MODIFICATIONS OF FIGS. 10-18 FIGS. 10-18 are modifications of the formof the invention shown in FIGS. 1-9. FIG. 10 shows a modifiedrestraining means in which the solenoid 147 is controlled by a switch260 operated by the vehicle seat 262. The switch is arranged to passacross a circuit contact whenever the vehicle-driver rests on the seatand also when he leaves the seat. The electrical contact is made onlytemporarily in each movement of the seat (which is a movable vehicleelement). Thus, the solenoid 147 is energized each time the driverenters or leaves the vehicle to render the speed regulator mechanisminoperative in a manner described above.

FIG. 11 is another form of transmission-operated restraining means inwhich the usual transmission lever 262 operates the conventional links264 and 266 to the transmission. Link 264 includes a pair of cam-actingtabs 268 which individually operates a pin 272 only when the selectorlever is moved out of (and into) drive position; this action closes aswitch 274 biased open by a spring 276 and which energizes solenoid 147to render the speed regulator mechanism inoperative in a mannerdescribed above. Since the switch is closed only when lever 264 is inmotion adjacent the drive position of selector 262, switch 274 is alwaysopen in all other positions of the selector lever. As stated previously,it is presently believed that the transmission operated restrainingmeans is best suited to provide a supplemental safety action. Hence, theswitch 152 operated by a door 151 is connected in parallel with switch274 to operate solenoid 147 in a manner described above. 7

' FIGS, 12 and 13 disclose another supplemental restraining means whichmay be added to provide more safety action, if warranted by the extraexpense. The form of selector mechanism illustrated in FIGS. 12 and 13of the present invention comprises means forming a chamber adapted to besealed by a cover to contain air under vacuum which maintains the sealwhen the manually-operated means is moved to provide such transfer ofvacuum; the cover forms one or more walls of the chamber and is movablewith and by the manual means to open the chamber to atmosphere andbreak" the vacuum when the manual means stands in its inoperativeposition.

In the modification of FIGS. 12 and 13, the cover 130 is not secured toplate portion 128, but is movable away therefrom, as shown in FIG. 13,by a pair of springs 158. At this time, chamber 132 is open to theatmosphere. The cover includes a sealing member 159, such as a gasket.

When the vehicle is at rest, the cover 130 is separated from plate 128by the springs 158, as shown in FIG. 13; at this time a valve 280 closesan orifice 282. After the engine is started, vacuum is produced in tube120 only to the valve 280, and the cover remains in the position shownin FIG. 13. When the driver pulls the knob 160, the left end of gear 138acts on disc-valve 142 to force the cover 130 against plate 128 to formand close the chamber 132, and all parts are then in the position shownin FIG. 12. At this time the orifice 282 is open, and substantially thefull manifold vacuum is transmitted to chamber 132, and tube 61'. Thevacuum in chamber 132 acts on the full exposed inside area of thecup-shaped rectangular cover 130 to overpower the force of springs 158.Thus the vacuum itself acts to hold the cover to close chamber 132 aslong as sufficient vacuum is maintained therein, so that the cover andits associated elements comprise pressure-sensitive means since it isactuated by the presence or absence of vacuum.

When the engine is shut off, the manifold vacuum dissipates in sourcetube 120. Without vacuum in chamber 132, the springs 158 move the cover130 to the position shown in FIG. 13. This action carries the knob 160to the position 160' (FIG. 3). Also, the knob can be manually moved tothis position by the driver any time he decides to render the speedcontrol device inoperative which opens valve 142; in this action, thevalve body or restrictor 154 is moved by the disc 156 to cover the inletof nipple 144, which dissipates the vacuum from chamber 132. At thistime, valve 280 closes orifice 282, and because of the large'a'ir-gap inchamber'132, the vehicle-driver must again deliberately pull knob 160into the position shown in FIG. 12. If this is performed while thevehicle is being driven, the cover is held by vacuum in its readyposition and the automatic throttle can be activated as before. Sincethis restraining means is operated by an engine function, it preferablyis used to supplement the dooroperated restraining means.

The construction and operation of the portion of the selector unit ofFIG. 12 described thus far is shown and described in more detail in myU.S. Pat. No. 3,222,227.

In the forms of the invention shown in FIGS. 12-14, simplifiedrestraining means are disclosed for rendering the speed controlmechanism inoperative when at least the driver's door is opened. In thisform of the invention, valve means are provided to be directly operatedby the door for bleeding air into the selective control unit to breakthe vacuum holding the pressuresensitive means, thereby rendering thesystem inoperative.

Referring to FIG. 12, a T hose nipple 286 is connected to hose nipple146 by suitable means, as by a piece of rubber tubing 146'. The tube 61is connected to another leg of the T-nipple 286 for transmitting thesource vacuum to valve unit 170. Another rubber tube 288 is connected atone end to the third leg of the T- nipple and at its other end to anipple-portion 289 of a valve member 290. The valve member may be madeof synthetic rubber of predetermined durometer or firmness for bondingto the nipple portion, which may be made of metal or plastic tubing. Thevalve member includes a double flange 291 which enables the valve memberto be inserted with a snap-action through a hole in a fixed portion 292of the vehicle with enough rigidity to hold the valve member firmly inits operating position. The valve member also includes a. sealingsurface or port means 294 which cooperates with a surface 151' of door151 to comprise the valve means operated by the door. Hence, thisadjacent door surface comprises an element of the valve means. One ormore convolutions 295 are molded in the rubber valve member in a mannerto accommodate production variations of the related vehicle elementswhile providing ample rigidity to maintain the surface 294 in sealingcontact with surface 151'.

In operation of the restraining means of FIG. 12, when the driver opensdoor 151, surface 151' leaves surface 294 which allows atmospheric airto enter chamber 132. Tubes 288, 146' and nipple 146 are large enough toenable the vacuum in chamber 132 to redice sufficiently for causingsprings 158 to move cover to the position shown in FIG. 13. In thisposition the speed control device is inoperative because valve 280 isclosed to preclude operation of the speed control system, until knob 160is pulled out deliberately by the driver after the door 151 is closed.

The form of the invention shown in FIG. 14 is the same as in FIG. 12except that a complete and separate valve means or unit is illustrated.In FIG. 14, a valve element 296 is slidable on a shaft 298 having anextension 298' for supporting the shaft. A spring 300 bears against aretainer pin 301 to urge the valve element 296 against another retainerpin 302; both pins are inserted through shaft 198 298 is axiallyslidable through and supported by the end portions of the valve unit, asillustrated. The valve element 296 cooperates with a seating orifice 303to seal the air passages when door 151 closes and acts on shaft 298. Aspring 304 urges shaft 298 leftwardly to open valve means 296 when thedoor is opened to allow air through a plurality of vent holes 305,thereby rendering the speed control system inoperative in the samemanner as for FIG. 12.

FIG. 14 also discloses pressure-regulating means which may be employedwhen desired to maintain or limit the vacuum acting on the cover 130;this pressure regulating means may also be used in the form shown inFIG. 12 if desired. Referring to FIG. 14, the T-nipple 286 includes avalve, such as a ball 305, which is urged against its orifice seat by aspring 306 to control the bleed of air past the valve and out throughorifice 282 to control or limit the vacuum in chamber 132. Orifice 282is made as small as possible without restricting the desired speed ofmovement of the servo-motor unit 7, but to maximize the effect of valve305.

Assume that spring 306 is selected to limit the vac uum in chamber 132at a maximum of 8 inches of mercury, for example. When the knob 160 ispulled out to close the cover 130 on plate 128, the valve 305 openswhenever the vacuum exceeds 8 inches of mercury, so that the vacuumacting on cover 130 and in tube 61 is maintained at about 8 inches ofmercury. If the manifold vacuum rises, the valve automatically opensmore to maintain this vacuum, and conversely. The servo spring 46 isdesigned to enable full travel of diaphragm 40 at vacuums less thanabout 6-7 inches of mercury, so that the servo-motor can operate thethrottle through its entire travel range unaffected by the limitedvacuum of 8 inches of mercury.

The pressure regulator means enables elimination of the disc-valve 142,the orifices 140, the valve body 154 and the adjusting disc or flange156, provided that shaft 136 is'secured to cover 130 and is not movablerelative thereto. Since the vacuum does not exceed 8 inches of mercuryin the assumed example, knob 160 can always be manually pushed to itsoff position without excessive resistance force. If the full vacuum ofinches of mercury acts on cover 132, as at low loads, the resistanceforce on knob 160 is too high for manual operation, and hence requiresthe valve 142 and shaft 136 movable in relation to cover 130, aspreviously described.

Also it is important to appreciate that the concepts disclosed in FIG.12-14 are useful in all types of speed control means to position thecontrol means; in an automatic speed control device, the hillcompensation is done automatically by a governor mechanism whichpositions the control means automatically, whereas in a manual speedcontrol device the control means is positioned manually so that thehill-compensation must be performed manually since no governor mechanismis provided. However, the requirements of the selective controlmechanism is the same in both the manual and automatic types of speedcontrols.

It is believed preferable that the forms of restraining means shown inFIGS. 12-14 are particularly useful when used in combination with theseveral means providing selective activation with subsequent automaticacceleration as illustrated in FIG. 9 (and in FIG. 16 to be discussed).

Since the original filing date of the parent application, I haveinterviewed a large number of owners of automotive speed controls. Someof these people indicated that they use their speed controls in citythroughstreets during light traffic as I have always done. However, alarge portion of those interviewed never use their speed controls in anykind of city driving, but only for highway and particularly turnpikedriving in moderate trafffic. If this indication eventually representsthe views of most speed-control users, I have disclosed in FIG. 15another form of the invention which enables use of resume speedoperation during highway and turnpike driving with complete safety, andalso with much simplification thereby reducing cost. Most of the presentspeed control devices are rendered completely inoperative upon each andevery brake actuation. However, this action is annoying during turnpikedriving in view of the many times the speed must be completely resetafter every brake-actuation for temporay speed reduction.

In the form of the invention disclosed in FIG. 15, means are provided inwhich the restraining means is operated to render the speed controlcompletely inoperative (locked out) each and every time the vehiclespeed falls below a predetermined value; but enables normal resume speedoperation including automatic acceleration at all speeds above thepredetermined speed, providing the knob is pulled out once by the driverafter this predetermined speed is attained and also providing that thevehicle speed is maintained above this low-limit speed, which are theexact circumstances for most turnpike driving.

If the predetermined lock-out speed is set at 30- 35 mph, for example,the device cannot be operated in most city driving situations; but thislock-out speed will not restrict turnpike operation in any manner. Ifthe lockout speed is set at a low value, such as 5-l0 mph for example,the speed control mechanism is locked out each and every time thevehicle stops, so the device cannot be used effectively for city drivingwith many stops; however it can be used with throughboulevard drivingduring light traffic. Regardless of the lock-out speed, the main intentof the system disclosed in FIG. 15 is to cause a complete lockout atleast each and every time the vehicle stops, while enabling completenormal operation with selective activation and resume speed operationduring highway driving.

In accordance with the specific inventive concept for the restrainingmeans of FIG. 15, a combination of means provides throttle-responsiveselective activation for causing automatic acceleration to a presetcruising governed speed, and further includes speed-responsive meansoperated at or below a predetermined vehicle speed to render the speedcontrol mechanism completely inoperative; but to enable normal manualselective activation and resume-speed action at all vehicle speedsbetween the predetermined speed and the governed speed after manualinitiation at least once by the driver when the vehicle speed exceedsthe predetermined speed.

The mechanism shown in FIG. 15 is a modification of the speed-sensingmechanism disclosed in FIG. 1, :and similar numerals denote the sameelements. Now referring to FIG. 15 (and also FIG. 12), thespeedresponsive means illustrated therein comprises the .bleed valvecooperating with a valve seating element 307 which includes a hosenipple at its other end. The bleed valve 110 and element 307 replacesthe valve member 290 (or valve unit in FIG. 14) to perform the samefunction as the valve member 290. The end of tube 288 which is securedto valve member 290 in FIG. 12 is now connected to the nipple of element307; but the remainder of the mechanism of FIG. 12 in combination withthe mechanism of FIG. 15 to comprise the restraining means is unchanged.In the illustrated speed-sensing means, the surface portion 88 isoperated by the centrifugal force of rollers 90 in opposition to spring116 (FIG. 1) which establishes the predetermined speed at which thevalve 110 closes. In FIG. 15, passage 55 does not communicate with valve110 or valve element 307, but by-passes around the valve element, asshown.

The operation of the restraining means illustrated in FIGS. 15 and 12 isas follows: When the vehicle is at rest, valve 110 is open and bleedsair into tube 288 and chamber 132 to preclude vacuum from acting oncover 130, all in the same manner as for the door-operated valve means290 in FIG. 12, and in FIG. 14. Vacuum is also precluded from cover 130at all speeds below a predetermined speed (such as 15 mph); when thevehicle accelerates to, this predetermined speed, the valve 110automatically closes as a result of the centrifugal force of rollers 90.The valve 110 is closed at all speeds above the predetermined speed, sothat the knob 160 can then be pulled deliberately by the driver forenabling him to activate the speed control device selectively at hisdiscretion at any desired speed with automatic acceleration or resumespeed action, all in the same manner as described above in relation toFIGS. 1

and 9.

Whenever the vehicle speed is reduced below the predetermined speed,valve 110 again opens and breaks the vacuum. acting on cover 130 so thatsprings 158 move the cover to the position shown in FIG. 13 forrendering the speed control mechanism inoperative, all as describedabove in relation to FIG. 12 when the tube 288 is bled by adoor-operated valve. By way of contrast in FIG. 15, tube 288 is bled bya speedresponsive valve.

The restraining means disclosed in FIGS. 15 and 12, in addition to itsadded safety, provides a simpler construction which enables a lower costof manufacture. Since vacuum is always precluded from cover 130 at leastwhenever the vehicle is stopped, there is no need for door-operatedmeans (nor for transmission or seatoperated means); whenever there is achange of drivers the device remains inoperative. Also the valve 216,spring 228 and disc 222 can be eliminated, since the valve 280 is alwaysclosed at least whenever the vehicle is not in motion.

While the restraining means of FIG. 15 is fluid operated, the inventiveconcept is intended to cover the use of any power source, such asequivalent electricpowered means, providing the activation is operatedin response to deliberate manual action by the driver with subsequentautomatic acceleration, and the device is automatically renderedinoperative by means responsive to a speed-change signal whenever thevehicle speed reduces below a predetermined lock-out speed.

If spring 116 is selected so that resume speed or selective activationwith automatic acceleration can only be used at highway speeds, as above40 mph for example, a higher rate of automatic acceleration would beacceptable than for automatic acceleration operation at lower vehiclespeeds.

If extra safety is desired at extra cost, both the dooroperated valve.of FIG. 12 (or FIG. 14) and the speedoperated valve can be used inparallel merelyby connecting another T-nipple in tube 61, for example.Then the door-operated valve bleeds chamber 132 in the event any failureof the speed-operated valve 110.

With the restraining means of FIGS. 15 and 12 in combination with thethrottle (or vacuum) operated activation means and subsequent automaticacceleration, as exemplified-in FIG. 9 (or in FIG. 2 of my U.S. Pat. No.3,348,626),'the acknowledged benefits of resume speed operation isrealized at very low cost and with complete safety.

In FIG. 16, alternate manual activating means are disclosed which areequivalent to the vacuum-operated activation means disclosed in relationto FIG. 9. FIG. 16 shows a modification of the form of the inventionshown in FIG. 9 in which common numerals denote common elements.Referring to FIGS. 9 and 16, a passage 308 connects chamber 186 withchamber 188, and includes a valve 309 which is normally spring-biased tocompletely close the passage. A solenoid 310 causes valve 309 totemporarily open passage 308 when the driver presses a spring-loadedbutton 311, which temporarily closes a switch 312 for enabling thevehicle battery to energize the solenoid. The button is preferablymounted near the drivers hand, such as on the steering wheel or ontheend of the turn signal lever.

In the operation of the activating means of FIG. 16, when the driverpresses button 311 to cause activation, the vacuum in chambers 186 and188 is the same; this condition immediately causes movement of valve 190(FIG. 9) downwardly, which opens port 196 and transmits vacuum to theservo-motor 7. The subsequent operation of the activation means andautomatic acceleration is the same as described previously in relationto FIG. 9.

If spring 206 is the same as described for FIG. 9, the selectiveactivation can be effected at the drivers discretion either bytemporarily advancing the accelerator or by pressing on button 311. Ifspring 206 is selected to operate valve 190 only at vacuums less thanone inch of mercury, for example, the device can be manually activatedonly by pressing button 311; this is true because the manifold vacuumcannot be reduced sufficiently to cause activation by advancing thethrottle temporarily. While the button-type of selective activation maybe used if desired, I prefer the throttleadvancement (vacuum-reduction)activation means because it is not necessary to press the button 311after each brake actuation.'Also, I consider the latter system to besafer because selective activation always occurs from a condition ofnormal driving, in which the drivers foot initially must be on theaccelerator.

In the forms of activation means shown in FIGS. 9 and 16, the termselective activation refers to the manual operation selectivelyperformed by the driver entirely at his discretion to cause theactivation. In FIG. 9, this manual operation comprises temporaryadvancement of the accelerator, whereas in FIG. 16 the manual operationcomprises depression of button 311. The activation is automatic in thesense that after this selective manual operation, the activation of theregulator mechanism and subsequent acceleration to the governed speed,as well as the maintenance of this governed speed are all automatic.

It is to be understood that the inventive concepts discussed in FIGS.12-16 are unchanged irrespective of the type of speed-selection meansemployed, regardless of whether the knob 160 and its associated elementsare used, or whether any other type of speed-setting means is used, suchas the lock-in'buttom type which presently are provided on someautomotive vehicles.

FIG. 17, which is viewed from the-top of the vehicle, discloses amodified curve-compensation mechanism which has the advantage ofseparate installation; this enables the device to be added for moreexpensive vehicles and omitted from lower cost vehicles. In FIG. 17 anormally closed bleed valve 316 is biased open by a spring 318 to rideon a cam 320 carried by a weight 322 secured to an arm 324 fulcrummed ata support 326 for swingable movements. A pair of springs 328 and 330 aresecured at one end to arm 324 and at another end to fixed supports.

In operation, when the highway curves to the right, the centrifugalforce of weight 322 causes movement thereof to the left (upward in FIG.17) which causes valve 316 to open and bleed air into passage 56. Thisaction reduces the regulated speed by an amount which increases as thehighway curvature increases. The weight gradually returns to theposition shown as the highway straightens out which shuts the air bleedat valve 316 to restore the original speed. When the highway curves tothe left the curve compensation action reverses. v

FIG. 18 discloses another modified curvecompensation means in which theair bleed valve 316 is normally closed and supported by a leaf spring332 fixed at one end and prebent to bias the valve in an openingdirection. The valve abuts a longitudinal cam 334 operated by a portionof the steering linkage such as the steering wheel shaft, or thesteering link 336 as illustrated in FIG. 18. In operation, whenever thehighway curves to the left, the steering wheel is turned to the leftwhich moves link 336 to the right (as in FIG. 18). This action enablescam 334 to open bleed valve 316 which reduces the governed speed as afunction of an increase in highway curvature in the same manner as forthe modification of FIG. 17. When the steering wheel is returned tonormal, valve 316 gradually closes to return the regulated speed to thehigher value established by rotation of knob.l60. When the highwaycurves to the right, the curve compensation reverses.

In considering the overall speed control system now completely describedabove,it is apparent that an additional advantage is the inherentsimplicity of installation. The selector unit 122 is secured to theunderside of any instrument panel, as by sheet metal screws. The brakevalve unit 170 is clamped to the steering post and made adjustable sothat actuator 208 is tangent to the usual suspended brake arm of anycar, and it is not necessary to connect parts to the brake arm. Thesensorbrain unit is connected in series to the conventional speedometershaft. Only one bracket is necessary to support the servo-motor unit 7,which is easily connected by chain 29 having an adjustable clamp orbracket securable to the carburetor lever, or any movable part of theaccelerator-carburetor linkage. In the forms of FIGS. l-4, the wires ofsolenoid 147 are connected to the door switch circuit, which is standardin all automobiles. If the preferred door lock-out means of FIG. 12 isemployed, no electric wires are required in the system. In the simplestform of the invention, as

illustrated in FIG. 15, no connections of any kind are required for thedoor, ignition or transmission.

Also, the Braille or tactile system of speed-setting is particularlyuseful in combination with the automatic acceleration action describedabove. The driver can feel the tactile indicator to set the desiredspeed (with surprising accuracy) without moving his sight from the road.After pulling the knob and depressing the brake pedal once, the driveraccelerates the vehicle by mild depression of the accelerator until alow speed such as 10-15 mph is attained. At any desired speed less thanthe preset speed, he then depresses the accelerator smoothly but firmlyuntil a click is heard, and removes his foot from the accelerator. Theregulator then automatically accelerates the vehicle to the preset speedand maintains this speed until rendered inactive (but not inoperative)by depressing the brake pedal. The entire improved operation isaccomplished by the sense of touch without any visual aids or referencelines.

I claim:

1. In a speed control device for an automotive vehicle including anengine having control means therefor nor mally advanced to increasevehicle-speed, and conversely, and including vehicle brake-actuatingmeans, said vehicle including an element manually movable by thevehicle-driver whenever the drive leaves the vehicle, and said vehiclealso including a source of fluid pressure that varies as a function ofthe position of said control means, the combination comprising; aregulator mechanism operatively associated with said control means andincluding a member operated by at least a portion of said pressure andadapted to produce forces acting on said control means in response to asignal accompanying a change in the speed of the vehicle to effectautomatic regulating movements of said control means in a directiontending to maintain a selected regulated speed of the vehicle, meansoperated by said brake-actuating means upon movements thereof forrendering said regulator mechanism inactive but not inoperative totransmit said forces to said control means, activating means operativelyassociated with said brake-actuating means and said mechanism andoperable in response to changes in said pressure varying as a result ofmanual advancement of said control means to automatically causeactivation of said mechanism with respect to said control means aftersaid advancement thereof by the vehicle-driver, valve means operable inresponse to said manual movement of said element for affecting the saidpressure-portion transmitted to said pressure-operated member, andrestraining means automatically operable in response to said operationof said valve means for rendering said mechanism inoperative and adaptedto prevent inadvertent activation of said mechanism until deliberatelyacti vated by the vehicle-driver.

2. The combination of means defined in claim 1, and a fluid circuitcommunicating with said source pressure, and selector valve means insaid circuit to control the transmission of said pressure-portion tosaid regulator mechanism, manual means operated by the vehicledrive forcausing movement of said selector valve means to a first position fortransmitting said pressureportion to said pressure-operated member, saidrestraining means including pressure-sensitive means operativelyassociated with said selector valve means and subjectable to fluidpressure in said circuit when said selector valve means stands in saidfirst position for

1. In a speed control device for an automotive vehicle including anengine having control means therefor normally advanced to increasevehicle-speed, and conversely, and including vehicle brake-actuatingmeans, said vehicle including an element manually movable by thevehicle-driver whenever the drive leaves the vehicle, and said vehiclealso including a source of fluid pressure that varies as a function ofthe position of said control means, the combination comprising; aregulator mechanism operatively associated with said control means andincluding a member operated by at least a portion of said pressure andadapted to produce forces acting on said control means in response to asignal accompanying a change in the speed of the vehicle to effectautomatic regulating movements of said control means in a directiontending to maintain a selected regulated speed of the vehicle, meansoperated by said brake-actuating means upon movements thereof forrendering said regulator mechanism inactive but not inoperative totransmit said forces to said control means, activating means operativelyassociated with said brake-actuating means and said mechanism andoperable in response to changes in said pressure varying as a result ofmanual advancement of said control means to automatically causeactivation of said mechanism with respect to said control means aftersaid advancement thereof by the vehicle-driver, valve means operable inresponse to said manual movement of said element for affecting the saidpressure-portion transmitted to said pressureoperated member, andrestraining means automatically operable in response to said operationof said valve means for rendering said mechanism inoperative and adaptedto prevent inadvertent activation of said mechanism until deliberatelyactivated by the vehicle-driver.
 2. The combination of means defined inclaim 1, and a fluid circuit communicating with said source pressure,and selector valve means in said circuit to control the transmission ofsaid pressure-portion to said regulator mechanism, manual means operatedby the vehicle-drive for causing movement of said selector valve meansto a first position for transmitting said pressure-portion to saidpressure-operated member, said restraining means includingpressure-sensitive means operatively associated with said selector valvemeans and subjectable to fluid pressure in said circuit when saidselector valve means stands in said first position for producing forcesacting on itself to maintain said selector valve means in said firstposition, anD means acting on said pressure-sensitive means upon saidoperations of said first-named valve means to change said sourcepressure for automatically causing movement of said selector valve meansto a second position for precluding said pressure-portion from acting onsaid pressure-operated member, until said pressure-sensitive means isagain subjected to said source pressure upon deliberate operation ofsaid manual means by the vehicle-driver.
 3. In a speed control devicefor an automotive vehicle including an engine having control meanstherefor normally operated by the vehicle-driver to increasevehicle-speed, and conversely, and including vehicle brake-actuatingmeans, said vehicle also including means providing a source of pressure,the combination comprising; a regulator mechanism operatively associatedwith said control means and including a pressure-responsive memberadapted to produce forces acting on said control means in response to asignal accompanying a change in the speed of the vehicle to causeautomatic regulating movements of said control means in a directiontending to maintain a selected regulated speed of the vehicle, releasemeans operated by said brake-actuating means upon normal movementsthereof for rendering said regulator mechanism inactive to transmit saidforces to said control means, activating means operatively associatedwith said mechanism and operated selectively by said driver to causeactivation of said mechanism with respect to said control means, andrestraining means including valve means automatically operable inresponse to a signal accompanying a change in vehicle speed foraffecting said pressure-responsive member and to render said mechanisminoperative.
 4. In a speed control device for an automotive vehicleincluding an engine having an intake passage for the flow of airtherethrough and a throttle therein which produces vacuum on thedownstream side thereof varying in accordance with changes in theposition of the throttle, said throttle being manually advanced toincrease vehicle speed accompanied by a reduction in said vacuum, andconversely, said vehicle including brake-actuating means, thecombination comprising; a regulator mechanism operatively associatedwith said throttle and adapted to produce forces acting thereon inresponse to a signal accompanying a change in the speed of the vehicleto cause automatic regulating movements of said throttle in a directiontending to maintain a selected regulated speed of the vehicle, meansoperated by said brake-actuating means upon normal movements thereof forrendering said regulator mechanism inactive but not inoperative totransmit said forces to said throttle, activating means operativelyassociated with said mechanism and including a pressure-responsivemember exposed to said intake passage vacuum and operable thereby toautomatically cause activation of said regulator mechanism with respectto said control means when said intake passage vacuum reduces to apredetermined value as a result of manual advancement of said throttleby the vehicle-driver, and restraining means operable in response to asignal accompanying a change in vehicle-speed for rendering saidmechanism inoperative, said automatic activation being effected at avehicle speed substantially lower than said regulated speed, and saidregulator mechanism being constructed and arranged to cause automaticacceleration of the vehicle from said lower speed to said regulatedspeed and tending automatically to maintain said selected regulatedspeed thereafter.
 5. In a speed control device for an automotive vehicleincluding an engine having control means therefor normally advanced toincrease vehicle-speed, and conversely, and including vehiclebrake-actuating means, said vehicle also including a door manuallymovable in opening and closing directions by the vehicle-driver, thecombination comprising; a source of fluid pressure variable in responseto changes in the position of said control means, a regulator mechAnismoperatively associated with said control means and including meansoperated by at least a portion of said pressure to produce forces actingon said control means in response to a signal accompanying a change inthe speed of the vehicle to effect automatic regulating movements ofsaid control means in a direction tending to maintain a selectedregulated speed of the vehicle, valve means operated by saidbrake-actuating means for movement into a first position upon normalmovements of said brake-actuating means for rendering said regulatormechanism inactive but not inoperative to transmit said forces to saidcontrol means, activating means operatively associated with saidmechanism and adapted to operate said valve means for affecting theoperation of said pressure operated means, said activating meansincluding a pressure responsive member exposed to said source pressurefor maintaining said valve means in said first position, and saidactivating means also including means to cause movement of said valvemeans to a second position when said source pressure changessufficiently upon partial advancement of said control means toautomatically effect said activation of said mechanism with respect tosaid control means, second valve means operable in response to saidmanual movements of said door for affecting the said pressure-portiontransmitted to said pressure-operated member, and restraining meansoperable in response to said operation of said second valve means forrendering said mechanism inoperative and adapted to prevent inadvertentactivation of said mechanism until deliberately activated by thevehicle-driver.
 6. In a speed control device for an automotive vehicleincluding an engine having control means therefor normally advanced toincrease vehicle-speed, and conversely, and including vehiclebrake-actuating means, said vehicle including means providing a fluidpressure that varies as a function of the position of said controlmeans, said vehicle also including a door manually movable in openingand closing directions by the vehicle-driver, the combinationcomprising; a regulator mechanism operatively associated with saidcontrol means and including servo-motor means operated by said fluidpressure to produce forces acting on said control means in response to asignal accompanying a change in the speed of the vehicle to effectautomatic regulating movements of said control means in a directiontending to maintain a selected regulated speed of the vehicle, a fluidcircuit including means for transmitting at least a portion of saidpressure to said regulator mechanism, activating means including valvemeans operatively associated with said circuit and movable to a firstposition by said brake-actuating means upon normal movements thereof tocontrol said fluid pressure for rendering said regulator mechanisminactive but not inoperative to transmit said forces to said controlmeans, said activating means including pressure-responsive meanscooperating with said valve means and subjected to said varying fluidpressure for maintaining said valve means in said first position aftersaid brake-actuating means is released by the vehicle-driver, saidpressure-responsive means being disposed to cause movement of said valvemeans to a second position in response to a change in said pressureproduced by advancing said control means, said valve means in saidsecond position being adapted to enable transmission of saidpressure-portion to said regulator mechanism for automatically effectingactivation of said mechanism with respect to said control means aftersaid advancement thereof by the vehicle-driver, second valve meansoperable in response to said manual movements of said door for affectingthe said pressure-portion transmitted to said pressure-operated member,restraining means operable in response to said operation of said secondvalve means for rendering said mechanism inoperative and to maintainsaid inoperative status when said door is moved in said closingdirection to prevent inadvertent activation of said mechanism untildeliberately activated by the vehicle-driver.
 7. In a speed controldevice for an automotive vehicle including an engine having controlmeans therefor operable by manual effort of the vehicle-driver, andincluding a vehicle-door movable in opening and closing directions, saidvehicle also including a source of fluid pressure produced as a resultof operation of the engine, the combination comprising; mechanismincluding a member operated by at least a portion of said pressure toregulate the position of said control means for establishing the speedof the vehicle independent of said manual effort on the control means bythe vehicle-driver, valve means mounted adjacent said door for directoperation thereby and operatively associated with said pressure sourceand said pressure-operated member for causing said fluidpressure-portion to be transmitted to said pressure-operated member, andrestraining means operated in response to said opening movements of saiddoor and said operation of said valve means for rendering saidpressure-operated member inoperative to regulate said control means. 8.In a speed control device for an automotive vehicle including an enginehaving control means therefor operable by manual effort of thevehicle-driver, and including a vehicle-door movable in opening andclosing directions, said vehicle also including a source of air undervacuum produced as a result of operation of the vehicle, the combinationcomprising: mechanism including a member operated by at least a portionof said vacuum to regulate automatically the position of said controlmeans for maintaining the speed of the vehicle independent of saidmanual effort on the control means by the vehicle-driver; valve meansmounted adjacent said door and operatively associated with said vacuumsource and said vacuum-operated member for enabling said vacuum-portionto be transmitted to said vacuum-operated member; selector valve meansto control the transmission of said vacuum portion to said mechanism;manual means operated by the vehicle-driver for causing movement of saidselector valve means to a first position for transmitting said vacuumportion to said vacuum-operated member; a chamber subjectable to saidsource vacuum; pressure-sensitive means comprising at least one wall ofsaid chamber and movable in relation to the other walls of said chamberfor closing said chamber or opening same to the surrounding atmosphere;said movable wall being normally open to the surrounding atmosphereabout its entire perimiter in its inoperative position; said movablewall being disposed to close said chamber when said selector valve meansis caused to move to its said first position by said manual means toproduce vacuum-caused forces acting on itself for maintaining saidselector valve means in said first position as long as said vacuum isproduced by the vehicle; and means acting on said movable wall uponsufficient change of said source vacuum for automatically causingmovement of said selector valve means to a second position forprecluding said vacuum portion from operating said vacuum-operatedmember and said movable wall until said selector valve means is againmanually caused to move to said first position deliberately by thevehicle-driver, to establish vacuum acting on said movable wall.
 9. In aspeed control device for an automotive vehicle including an enginehaving control means therefor operable by manual effort of thevehicle-driver, and including a vehicle-door movable in opening andclosing directions, said vehicle also including a source of fluidpressure produced as a result of operation of the engine, thecombination comprising: a regulator mechanism including a memberoperated by at least a portion of said pressure to regulate the positionof said control means for establishing the speed of the vehicleindependent of said manual effort on said control means by said driver;valve means mounted adjacent said door for direct operation thereby andoperatively associated with said pressure source and saidpressure-operated member for controlling the transmission of said fluidpressure to said pressure-operated member; a portion of said doorcomprising movable sealing means for said valve means; restraining meansoperated in response to opening movements of said door and said valvemeans for rendering said pressure-operated member inoperative toregulate said control means; and manually operated means operativelyassociated with said restraining means to enable actuation thereofdeliberately and consciously by the vehicle-driver for enablingtransmission of said pressure-portion to said pressure-operated member.10. In a control device for an automotive vehicle having an engine andcontrol means for said engine, said vehicle also having brake-actuatingmeans and having at least one door manually movable by thevehicle-driver, the combination comprising: a regulator mechanismoperatively associated with said control means and including a memberoperated by at least a portion of said pressure to regulate the positionof said control means for establishing the speed of the vehicleindependent of foot pressure on said control means by said driver;release means operated by said brake-actuating means in normal movementsthereof to at least temporarily inactivate said regulator mechanism withrespect to said control means; valve means adjacent said door foroperation thereby and operatively associated with said pressure sourceand said pressure-operated member for controlling the transmission ofsaid fluid pressure to said pressure-operated member; restraining meansincluding pressure-sensitive means automatically operable upon saidoperation of said valve means for when said door is opened renderingsaid pressure-operated member inoperative to regulate said controlmeans; and manually operated means operatively associated with saidpressure-sensitive means to enable actuation thereof deliberately andconsciously by said vehicle-driver for causing transmission of saidpressure-portion to said pressure-operated member when said door isclosed.
 11. In a speed control device for an automotive vehicleincluding an engine having control means therefor normally advanced toincrease vehicle-speed, and conversely, and also including a source offluid pressure, said vehicle having brake-actuating means and avehicle-door movable by the vehicle-driver in opening or closingdirctions, the combination comprising; a regulator mechanism operativelyassociated with said control means and adapted to produce forces actingthereon in response to a signal accompanying a change in the speed ofthe vehicle to effect automatic regulating movements of said controlmeans in a direction tending to maintain a regulated speed of thevehicle, said mechanism including a pressure-responsive memberoperatively connected to said control means for actuation thereof andsubjected to at least a portion of said source pressure to enable saidautomatic regulation of said control means, release means operated bysaid brake-actuating means upon normal movements thereof at least torender said regulator mechanism inactive, manually operable selectormeans including valve means movable into a first position to enabletransmission of said pressure to said pressure-responsive member, saidselector means being adapted to enable said valve means to remain insaid first position during operation of said regulator mechanismindependent of and unaffected by said operations of said brake-actuatingmeans, means operated by said door to automatically cause said valvemeans to move to a second position when said door is opened to precludetransmission of said pressure-portion to said pressure-operated member,and said selector means being adapted to enable said valve means toreside in said second position until said valve means is moved into saidfirst position deliberately and consciously by the vehicle-driver. 12.In a speed control deVice for an automotive vehicle including an enginehaving control means therefor normally advanced to increasevehicle-speed, and conversely, and also including a source of fluidpressure, said vehicle having brake-actuating means and a vehicle-doormovable by the vehicle-driver in opening or closing directions, thecombination comprising; a regulator mechanism operatively associatedwith said control means and adapted to produce forces acting thereon inresponse to a signal accompanying a change in the speed of the vehicleto effect automatic regulating movements of said control means in adirection tending to maintain a regulated speed of the vehicle, saidmechanism including a pressure-responsive member operatively connectedto said control means for actuation thereof and subjected to at least aportion of said source pressure to enable said automatic regulation ofsaid control means, first valve means operable in a first positionthereof to enable said source pressure to operate said pressureresponsive member, release means operated by said brake-actuating meansupon normal movements thereof to cause operation of said first valvemeans to a second position thereof at least for rendering said regulatormechanism inactive, manually operable selector means including secondvalve means in a first position thereof to enable transmission of saidpressure to said pressure responsive member, said selector means beingdisposed to enable said second valve means to remain in said firstposition during operation of said regulator mechanism independent of andunaffected by said operations of said brake-actuating means, meansoperated by said door to automatically cause said second valve means tomove to a second position when said door is opened for rendering saidregulator mechanism inoperative to operate said control means, and saidselector means being adapted to enable said second valve means to residein its said second position until said second valve means is moveddeliberately and consciously by the vehicle-driver to its said firstposition.
 13. In a speed control device for an automotive vehicleincluding an engine having control means therefor operable by manualeffort of the vehicle-driver, and including vehicle brake-actuatingmeans, said vehicle also including a door movable whenever the driverleaves the vehicle, the combination comprising: a regulator mechanismoperatively associated with said control means and adapted to produceforces acting thereon in response to a signal accompanying a change inthe speed of the vehicle to effect automatic regulating movements ofsaid control means in a direction tending to maintain a selectedregulated speed of the vehicle independent of said manual effort on thecontrol means by the vehicle-driver; means operated by saidbrake-actuating means upon normal movements thereof at least forrendering said regulator mechanism inactive; and restraining meansincluding a pressure-sensitive member and valve means directly operatedby said door for controlling said member to automatically render saidregulator mechanism inoperative with respect to said control meanswhenever said driver leaves said vehicle.
 14. In a speed control devicefor an automotive vehicle including an engine having control meanstherefor operable by manual effort of the vehicle-driver, and includingvehicle brake-actuating means, said vehicle also including a doormovable whenever the driver leaves the vehicle, the combinationcomprising; a regulator mechanism operatively associated with saidcontrol means and adapted to produce forces acting thereon in responseto a signal accompanying a change in the speed of the vehicle to effectautomatic regulating movements of said control means in a directiontending to maintain a selected regulated speed of the vehicleindependent of said manual effort on the control means by thevehicle-driver, means operated by said brake-actuating means upon normalmovements thereof for rendering said regulator mechanism inactive butnot iNoperative to transmit said forces to said control means, manuallyoperable activating means operatively associated with said regulatormechanism to effect activation of said mechanism with respect to saidcontrol means, and restraining means including a pressure-sensitivemember and valve means directly operated by said door for controllingsaid member to automatically render said regulator mechanism inoperativewith respect to said control means whenever said driver leaves saidvehicle.
 15. In a control device for an automotive vehicle having anengine and control means therefor operable by manual effort of thevehicle-driver, said vehicle including an electric circuit, and alsoincluding a transmission and selector means therefor manually movable bythe vehicle-driver into at least driving and non-driving positions, thecombination comprising; means to position said control means toestablish the operating speed of the vehicle independent of said manualeffort on the control means by the vehicle-driver, said selector meansincluding a single switch adapted to be operated only while saidselector means stands on either side of said driving position duringtransient movements thereof to and from said driving position, andrestraining means including an electric device in said circuit adaptedto be energized temporarily when said switch is operated upon movementof said selector means from said driving position to at least one saidnon-driving position to render said positioning means inoperative withrespect to said control means.
 16. In a control device for an automotivevehicle having an engine and control means therefor operable by manualeffort of the vehicle-driver, said vehicle including an electriccircuit, and also including a transmission and selector means thereformanually movable by the vehicle-driver into at least driving andnon-driving positions, the combination comprising; means to positionsaid control means to establish the operating speed of the vehicleindependent of said manual effort on the control means by thevehicle-driver, said selector means including switch means adapted to beoperated only while said selector means stands on either side of saiddriving position during transient movements thereof to and from saiddriving position, said selector means including cam means acting on saidswitch means to cause said operation thereof upon said movements of saidselector means to either side of said driving position, and restrainingmeans including an electric device in said circuit adapted to beenergized temporarily when said switch means is operated upon movementof said selector means from said driving position to at least one saidnon-driving position to render said positioning means inoperative withrespect to said control means.
 17. In a speed control device for anautomotive vehicle including an engine having control means therefornormally advanced to increase vehicle-speed, and conversely, whenoperating on roads and highways, the combination comprising, a regulatormechanism operatively associated with said control means and adapted toproduce forces acting thereon in response to a signal accompanying achange in the speed of the vehicle to effect automatic regulatingmovements of said control means in a direction tending to maintain aselected regulated speed of the vehicle, and automaticcurve-compensation means including only one weight responsive solely tocentrifugal forces produced by said weight as a result of changes in thecurvature of said road both to the left or right and operativelyassociated with said regulator mechanism for automatically causing thevehicle-speed to reduce from said regulated speed by an amount varyingas a function of said road curvature, said curve-compensation meansbeing constructed and arranged to automatically return the vehicle speedto said regulated speed gradually as said road curvature diminishes tozero, and means operatively associated with said weight for restrictingthe movements thereOf solely to a direction substantially transverse tothe direction of the vehicle for rendering said weight independent ofthe effects of vehicle acceleration and deceleration.
 18. In a speedcontrol device for an automotive vehicle including an engine havingcontrol means therefor normally advanced to increase vehicle-speed, andconversely, when operating on roads and highways, the combinationcomprising; a regulator mechanism for effecting automatic regulatingmovements of said control means in a direction tending to maintain aselected regulated vehicle speed, said mechanism includingpressure-responsive means operatively connected to said control meansfor causing said speed-regulating movements thereof, a fluid circuithaving a source of fluid pressure for operating said pressure-responsivemeans, said regulator mechanism also including sensing means responsiveto changes in a signal accompanying a change in vehicle speed to produceforces reflecting said change of vehicle speed, means operated by saidsensing means forces for controlling pressures in said circuit acting onsaid pressure-responsive means for causing said speed-regulatingmovements thereof, automatic curve-compensation means including valvemeans operatively associated with said circuit and movable solely inaccordance with increases in the curvature of said road both to the leftor right independent of vehicle speed-changes for modifying saidpressure in said circuit acting on said pressure-responsive means toautomatically cause the vehicle-speed to reduce from said selected speedby an amount varying as a function of said road-curvature, and saidcurve-compensation means being constructed and arranged to automaticallyrestore said circuit pressure for returning the vehicle-speed to saidselected speed gradually as said road-curvature diminishes to zero. 19.In a speed control device for an automotive vehicle including an enginehaving control means therefor normally advanced to increasevehicle-speed, and conversely, when operating on roads and highways, thecombination comprising; a regulator mechanism for effecting automaticregulating movements of said control means in a direction tending tomaintain a selected regulated vehicle speed, said mechanism includingpressure-responsive means operatively connected to said control meansfor causing said speed-regulating movements thereof, a fluid circuithaving a source of fluid pressure for operating said pressure-responsivemeans, said regulator mechanism also including sensing means responsiveto changes in a signal accompanying a change in vehicle speed to produceforces reflecting said change of vehicle speed, pilot means operated bysaid sensing means forces for controlling pressures in said circuitacting on said pressure-responsive means for causing saidspeed-regulating movements thereof, automatic curve-compensation meansincluding valve means operatively associated with said circuit andmovable solely in accordance with increases in the curvature of saidroad for modifying said pressure in said circuit acting on saidpressure-responsive means to automatically cause the vehicle-speed toreduce from said selected speed by an amount varying as a function ofsaid road-curvature, said curve-compensation means being constructed andarranged to automatically restore said circuit-pressure for returningthe vehicle-speed to said selected speed gradually as saidroad-curvature diminishes to zero, and said curve-compensation meansincluding weight means to operate said valve means in response tochanges in the centrifugal forces produced on said weight means whensaid vehicle traverses a road curve to cause said pressure-modifyingmovements of said valve means, and means operatively associated withsaid weight means for restricting the movements thereof solely to adirection substantially transverse to the direction of the vehicle forrendering said weight means independent of the effects of vehicleacceleration and deceleration.
 20. In a speed coNtrol device for anautomotive vehicle including an engine having control means therefornormally advanced to increase vehicle-speed, and conversely, whenoperating on roads and highways, said vehicle including a steeringmechanism having an element movable by the vehicle-driver to turn thevehicle, the combination comprising; a regulator mechanism operativelyassociated with said control means and adapted to produce forces actingthereon in response to a signal accompanying a change in the speed ofthe vehicle to effect automatic regulating movements of said controlmeans in a direction tending to maintain a selected regulated speed ofthe vehicle, and automatic curve-compensation means responsive tochanges in the position of said element when moved away from a neutralposition of said steering mechanism on road curves and operativelyassociated with said regulator mechanism for automatically causing thevehicle-speed to reduce from said regulated speed by an amount varyingin accordance with the curvature of said road, and automaticallyreturning the vehicle-speed to said regulated speed gradually when saidsteering mechanism is returned to said neutral position as saidroad-curvature diminishes to zero.
 21. In a speed control device for anautomotive vehicle including an engine having control means therefornormally advanced to increase vehicle-speed, and conversely, whenoperating on roads and highways, said vehicle including a steeringmechanism movable by the vehicle-driver to turn the vehicle, thecombination comprising; a regulator mechanism for effecting automaticregulating movements of said control means in a direction tending tomaintain a selected regulated vehicle speed, said mechanism includingpressure-responsive means operatively connected to said control meansfor causing said speed-regulating movements thereof, a fluid circuithaving a source of fluid pressure for operating said pressure-responsivemeans, said regulator mechanism also including sensing means responsiveto changes in a signal accompanying a change in vehicle speed to produceforces varying as a function of vehicle speed, means operated by saidsensing means forces for controlling pressures in said circuit acting onsaid pressure-responsive means for causing said speed-regulatingmovements thereof, automatic curve-compensation means including valvemeans operatively associated with said circuit and movable in responseto changes from a neutral position of said steering mechanism formodifying said pressure in said circuit acting on saidpressure-responsive means to automatically cause the vehicle-speed toreduce from said selected speed by an amount varying in accordance withthe curvature of said road, and to automatically return thevehicle-speed to said selected speed gradually as said road-curvaturediminishes to zero.
 22. In a control device for an automotive vehiclehaving an engine and control means for said engine, said vehicleincluding a source of pressure fluid, said vehicle also havingbrake-actuating means and having at least one door manually movable bythe vehicle-driver, the combination comprising: means operativelyassociated with said control means to regulate the position thereof forestablishing the speed of the vehicle independent of foot pressure onsaid control means by said driver; release means operated by saidbrake-actuating means upon normal movements thereof to at leasttemporarily inactivate said positioning means with respect to saidcontrol means; restraining means including a movable pressure-sensitivemember subjectable to an actuating pressure transmitted from saidpressure-source for enabling operation of said positioning means, saidrestraining means also including valve means communicating fluidicallywith said member and operated in response to opening movements of saiddoor to modify said actuating pressure for causing movement of saidmember to automatically render said positioning means inoperative withrespect to said control means, and incapable of inadvertent operationafter said door is closed until activated deliberately by thevehicle-driver.
 23. In a control device for an automotive vehicle havingan engine and control means for said engine, said vehicle including asource of fluid pressure, said vehicle also having brake-actuating meansand having at least one door manually movable by the vehicle-driver, thecombination comprising: means operatively associated with said controlmeans to regulate the position thereof for establishing the speed of thevehicle independent of foot pressure on said control means by saiddriver; release means operated by said brake-actuating means upon normalmovements thereof to at least temporarily inactivate said positioningmeans with respect to said control means; restraining means including amovable pressure-sensitive member subjectable to an actuating pressuretransmitted from said pressure source for enabling operation of saidpositioning means, said restraining means also including valve meanscommunicating fluidically with said member and mounted adjacent saiddoor for direct operation thereby upon opening movements thereof tomodify said actuating pressure for causing movements of said member torender said positioning means inoperative with respect to said controlmeans, said restraining means being constructed and arranged to beincapable of inadvertent operation after said door is closed untiloperated deliberately by the vehicle-driver.
 24. The combination ofmeans defined in claim 23, and said source of pressure comprising airproduced by a component in said vehicle; and said valve means includingopen port means secured to a fixed portion of said vehicle adjacent amovable portion of said door and communicating with saidpressure-sensitive member; said door including surface means cooperatingwith said port means to comprise a portion of said valve means forclosing said port means from the atmosphere whenever said door isclosed, and to open said port means to the atmosphere whenever said dooris opened for changing the pressure acting on said member sufficientlyto render said positioning means inoperative.
 25. The combination ofmeans defined in claim 23, and second valve means including a movablevalve element and operatively associated with said restraining means tocontrol the transmission of said actuating pressure to saidpressure-sensitive member; manual means operated by the vehicle-driverfor causing movement of said movable valve element to a first positionfor effecting said transmission of said actuating pressure to saidpressure-sensitive member while said door is closed for producing forcesacting on itself to maintain said movable valve element in said firstposition; and means acting on said pressure-sensitive member uponsufficient change of said actuating pressure for automatically causingmovement of said movable valve element to an inoperative position forprecluding said actuating pressure from acting on saidpressure-sensitive member, until said member is again subjected to saidactuating pressure upon deliberate operation of said manual means by thevehicle-driver to cause movement of said valve element to said firstposition.
 26. In a control device for an automotive vehicle having anengine and control means for said engine, said engine including a sourceof fluid pressure, said vehicle also having brake-actuating means andhaving at least one door manually movable by the vehicle-driver, thecombination comprising: means operatively associated with said controlmeans to regulate the position thereof for establishing the speed of thevehicle independent of foot pressure on said control means by saiddriver; release means operated by said brake-actuating means upon normalmovements thereof to temporarily render said positioning means inactivebut not inoperative with respect to said control means; activating meansoperable selectively by the vehicle-driver at his discretion to causeactivation of said positioning means with respecT to said control means;said device being constructed and arranged to provide automaticacceleration from the speed at which said selective activation occurs tothe speed established by said positioning means; restraining meansincluding a movable pressure-sensitive member subjectable to anactuating pressure transmitted from said pressure source for enablingoperation of said positioning means, said restraining means alsoincluding valve means communicating fluidically with said member andmounted adjacent said door for direct operation thereby upon openingmovements thereof to modify said actuating pressure for causing movementof said member to render said positioning means inoperative with respectto said control means, said restraining means being constructed andarranged to be incapable of inadvertent operation after said door isclosed until deliberately operated by the vehicle-driver.
 27. In a speedcontrol device for an automotive vehicle including an engine havingcontrol means therefor, said vehicle also including a source of fluidpressure produced as a result of operation of the vehicle, thecombination comprising: mechanism including means to regulate theposition of said control means for establishing the speed of the vehicleindependent of foot pressure on said control means by thevehicle-driver; pressure-sensitive means for controlling the operativerelationship of said positioning means with respect to said controlmeans; manual means operatively associated with said pressure-sensitivemeans and operable by said driver to cause movement of saidpressure-sensitive means from an inoperative position to an operativeposition, and conversely; said pressure-sensitive means in saidoperative position being subjectable to at least a portion of saidsource pressure for producing forces acting on itself to maintain samein said operative position for enabling said operative relationship ofsaid positioning means and said control means; means acting on saidpressure-sensitive means upon sufficient change of said source pressurefor causing movement of said pressure-sensitive means to saidinoperative position to preclude said pressure-portion from acting onsaid pressure-sensitive means for terminating said operativerelationship, until said pressure-sensitive means is again subjected tosaid source pressure upon deliberate operation of said manual means bysaid driver; and pressure-regulating means operatively associated withsaid pressure-source for limiting to a predetermined value saidpressure-portion when acting on said pressure-sensitive means, forenabling said manual movement of said pressure-sensitive means to saidinoperative position without requiring excessive resistance force tooperate said manual means.
 28. In a speed control device for anautomotive vehicle including an engine having control means therefornormally advanced to increase vehicle-speed, said vehicle includingbrake-actuating means, the combination comprising: a regulator mechanismoperatively associated with said control means and adapted to produceoperating forces acting thereon in response to a signal accompanying achange in the speed of the vehicle to cause automatic regulatingmovements of said control means in a direction tending to maintain aselected regulated speed of the vehicle; restraining means including apressure-sensitive member and valve means responsive to a change in asignal accompanying a change in vehicle speed for affecting said memberto render said regulator mechanism inoperative with respect to saidcontrol means whenever the vehicle-speed reduces below a predeterminedvalue; and release means operated by said brake-actuating means uponnormal movements thereof for rendering said regulator mechanisminactive.
 29. The combination of means defined in claim 28, andactivating means operable selectively by said driver at any speedbetween said predetermined speed and said regulated speed to causeactivation of said mechanism with respect to said control means Entirelyat the discretion of said driver; said regulator mechanism upon saidselective being constructed and arranged to cause automatic accelerationof the vehicle from the activation speed to said regulated speed andtending automatically to maintain said regulated speed thereafter. 30.The combination of means defined in claim 28, and activating meansoperable selectively by said driver at any speed between saidpredetermined speed and said regulated speed to cause activation of saidmechanism with respect to said control means entirely at the discretionof said driver; said regulator mechanism upon said activation beingconstructed and arranged to cause automatic acceleration of the vehiclefrom the activation speed to said regulated speed and tendingautomatically to maintain said regulated speed thereafter; and saidactivating means including manually-operated means having an elementmounted adjacent the driver and operable by the driver''s hand at hisdiscretion when the vehicle-speed stands between said predeterminedspeed and said regulated speed to cause said activation of saidregulator mechanism and said subsequent automatic acceleration to saidregulated speed.
 31. In a speed control device for an automotive vehicleincluding an engine having control means therefor normally advanced bythe vehicle-driver to increase vehicle-speed, said vehicle alsoincluding brake-actuating means, the combination comprising: a regulatormechanism for effecting automatic regulating movements of said controlmeans in a direction tending to maintain a selected regulated vehiclespeed; said mechanism including pressure-responsive means operativelyconnected to said control means for causing said speed-regulatingmovements thereof, a fluid circuit having a source of fluid pressure foroperating said pressure-responsive means; said regulator mechanism alsoincluding sensing means responsive to changes in a signal accompanying achange in vehicle speed to produce forces reflecting said change ofvehicle speed; pilot means operated by said sensing means forces forcontrolling pressures in said circuit acting on said pressure-responsivemeans for causing said speed-regulating movements thereof; restrainingmeans including means responsive to a change in a signal accompanying achange in vehicle speed to maintain said regulator mechanism inoperativewhen the vehicle-speed is at least initially below a predeterminedvalue, and to preclude operation of said mechanism until same isactivated manually at least once by said driver when the vehicle-speedexceeds said predetermined value; said restraining means includingpressure-sensitive means communicating with said circuit to control thetransmission of said fluid pressure to said circuit for enablingoperation of said pressure responsive means; and said signal-responsivemeans including second valve means responsive to said speed-signalchange for controlling operation of said pressure-sensitive means; andrelease means operated by said brake-actuating means upon normalmovements thereof for rendering said regulator mechanism inactive. 32.The combination of means defined in claim 31, and selective activatingmeans including means operatively associated with said mechanism andoperated in response to movement of said control means upon deliberateadvancement thereof by said driver to cause activation of said mechanismwith respect to said control means; said selective activation beingeffected at a vehicle speed between said predetermined speed and saidregulated speed; and said regulator mechanism being constructed andarranged to cause automatic acceleration of the vehicle from saidactivation speed to said regulated speed and tending automatically tomaintain said regulated speed thereafter.
 33. In a speed control devicefor an automotive vehicle including an internal combustion engine havingan air intake passage and a throttle operatively mounted in said passageproducing a vacuum on the downstream side of the throttle, wHich vacuumreduces as the throttle is advanced by the vehicle-driver to establishthe speed of the vehicle, said vehicle also including brake-actuatingmeans, the combination comprising: a regulator mechanism operativelyassociated with said control means and adapted to produce operatingforces acting thereon in response to a signal accompanying a change inthe speed of the vehicle to cause automatic regulating movements of saidcontrol means in a direction tending to maintain a regulated speed ofthe vehicle; means restraining responsive to a change in a signalaccompanying a change in vehicle speed to render said regulatormechanism inoperative whenever the vehicle-speed reduces below apredetermined value, and to preclude operation of said mechanism untilthe vehicle speed exceeds said predetermined value; release meansoperated by said brake-actuating means upon normal movements thereof forrendering said regulator mechanism inactive but not inoperative wheneverthe vehicle speed exceeds said predetermined value; selective activatingmeans operatively associated with said mechanism and including apressure-responsive member communicating with said intake passage vacuumand operable thereby to cause activation of said mechanism with respectto said control means at the discretion of said driver when said intakepassage vacuum reduces to a predetermined value as a result ofdeliberate manual advancement of said throttle by said driver, saidselective activation being effected at a vehicle-speed between saidpredetermined speed and said regulated speed; and said regulatormechanism being constructed and arranged to cause automatic accelerationof the vehicle from said activation speed to said regulated speed andtending automatically to maintain said regulated speed thereafter. 34.In a speed control device for an automotive vehicle including an enginehaving control means therefor normally advanced to increasevehicle-speed, and conversely, and including vehicle brake-actuatingmeans, said vehicle including a source of fluid pressure, and alsoincluding an element manually movable by the vehicle-driver incident tonormal operation of the vehicle, the combination comprising; a regulatormechanism including a fluid servo-motor adapted to be operativelyconnected to said control means to produce forces acting thereon, afluid circuit communicating with said pressure source and with saidservo-motor, said regulator mechanism including pilot valve means fordirecting at least a portion of said pressure to said servo-motor inresponse to a signal accompanying a change in the speed of the vehiclefor causing stable automatic regulating movements of said control meansin a direction tending to maintain a selected regulated speed of thevehicle, release means operated by said brake-actuating means uponnormal movements thereof for rendering said regulator mechanism inactivebut not inoperative to transmit said forces to said control means,activating means operable selectively by the vehicle-driver to causeimmediate activation of said mechanism with respect to said controlmeans entirely at the discretion of said driver, said regulatormechanism upon said activation being constructed and arranged to causeautomatic acceleration of the vehicle from the speed at which saidactivation occurs to said selected regulated speed and tendingautomatically to maintain said regulated speed thereafter, restrainingmeans automatically operable in response to movements of said element torender said mechanism inoperative, selector valve means in said circuitto control the transmission of said pressure-portion to said regulatormechanism, manual means operated by the vehicle-driver for causingmovement of said selector valve means to a first position fortransmitting said pressure-portion to said servo-motor,pressure-sensitive means operatively associated with said selector valvemeans and subjectable to fluid pressure in said circuit when saidselector valve means stands in said first posItion for producing forcesacting on itself to maintain said selector valve means in said firstposition, and means acting on said pressure-sensitive means uponsufficient change of said circuit pressure for automatically causingmovement of said selector valve means to a second position forprecluding said pressure from acting on said servo-motor, until saidpressure-sensitive means is again subjected to said circuit pressureupon deliberate operation of said manual means by the vehicle-driver.35. The combination of means defined in claim 34, and said fluidcomprising air under vacuum, and a chamber subjectable to said vacuum insaid circuit, said pressure-sensitive means comprising at least one wallof said chamber and movable in relation to the other walls of saidchamber for closing said chamber or opening same to the surroundingatmosphere, said movable wall being normally open to the surroundingatmosphere about its entire perimeter in its inoperative position, saidmovable wall being disposed to close said chamber when said selectorvalve means is caused to move to its said first position by said manualmeans to produce vacuum-caused forces acting on itself for maintainingsaid selector valve means in said first position as long as said vacuumis produced by the vehicle, and said means acting on said movable wallupon said change of said source vacuum automatically causing movement ofsaid selector valve means to said second position for precluding saidcircuit vacuum from operating said servo-motor and said movable walluntil said selector valve means is again manually caused to move to saidfirst position deliberately by the vehicle-driver, to establish vacuumacting on said movable wall.
 36. The combination of means defined inclaim 3, and said source of pressure comprises air under vacuum; andsaid restraining means also including a vacuum-sensitive membersubjectable to at least a portion of said source vacuum and affected byoperation of said valve means to render said mechanism inoperativewhenever the vehicle speed is less than a predetermined value; a chambersubjectable to said source vacuum; said vacuum-sensitive membercomprising at least one wall of said chamber and movable in relation tothe other walls of said chamber for closing said chamber or opening sameto the surrounding atmosphere; said movable wall being normally open tothe surrounding atmosphere about its entire perimeter in its inoperativeposition; manual means operable by the vehicle-driver for causingmovement of said vacuum-sensitive member to a first position forenabling said vacuum portion to be transmitted to saidpressure-responsive member; said movable wall being disposed to closesaid chamber when said vacuum-sensitive member is caused to move to itssaid first position by said manual means to produce vacuum-caused forcesacting on itself for maintaining said movable wall in its operativeposition as long as said vacuum is produced by the vehicle; and meansacting on said movable wall upon sufficient change of said vacuumportion for automatically causing movement of said movable wall to saidinoperative position for precluding said vacuum portion from operatingsaid pressure-responsive member and said movable wall until saidvacuum-sensitive member is again manually caused to move to said firstposition deliberately by the vehicle-driver, to establish vacuum actingon said movable wall.
 37. The combination of means defined in claim 36,and vent valve means operatively connected to said manual means formovements thereby independent of said movable wall to vent said chamberto air at atmospheric pressure for dissipating said vacuum therein atthe discretion of said vehicle-driver.